Rogue of the Night
by KillerGeishaYumi
Summary: Modern. Hiccstrid. Dragon!Hiccup. Spiderman-esque, I guess, because Hiccup knows almost nothing about the very powers that allow him to become a vigilante superhero. Does the Crime genre mean cops and detectives chasing bad guys, or should I change that to Mystery?
1. Chapter 1

It was safe to say, the operation was not going well.

Murdock was shouting his demands from the roof of a two-story building while holding a gun to a little boy's head. Stoik Haddock had little patience for diplomacy in situations like this, and was trying to figure out the quickest way to that roof without attracting Murdock's attention. It was after sundown, which was both good and bad; good because it gave a strike team some much-needed cover to get away from the police vehicles and into the building, bad because most of his best men were on high alert for another weredragon night raid.

Which left Stoik with _one_ seasoned warrior – who had an old prosthetic leg and therefore was unable to utilize the speed necessary to fight dragons – and a handful of _junior officers_.

 _Damned Helheim's Gate…_

Fisher was looking the blueprints over, muttering to himself about the building's "architectural integrity." Giving him those papers had been a stroke of genius; ever since the near-disaster of the last night raid, he absolutely _had_ to have something to occupy his highly-developed mind when he was on the streets after dark.

Scott, Rowan and Tomah wanted to charge in with full battle cries; Gob had to practically sit on them, insisting that without a _plan_ they would only succeed in getting that poor boy shot. Even bowing to the logic, they were still grumbling so much that Stoik was beginning to have uncharitable thoughts involving handcuffs and backseats of the police cars.

Astrid was better-behaved, but she was clearly itching to sling some bullets. Stoik was tempted to give the order – she was an excellent shot – but it would be better for the force if Murdock could be taken alive. Besides, he would have to put the three hotheads in the back of the police cars first: if _she_ started shooting, they would pull out their guns too.

And Hiccup was…nowhere to be found.

"What do you think that Murdock was smoking?" Gob asked casually. "He's not getting a helicopter to come to that roof; it's too crowded."

Distracted from the little matter of Hiccup avoiding him since their Talk, Stoik looked up. This particular building was old, flanked on either side by much newer and larger ones that crowded in close; a particularly daring person could tightrope right over it and not be taking excessive risk. Gob was right, there wasn't a lot of room for a helicopter – even if one had been called, which it hadn't.

"Off the record for now, I think he's a Berserk," Stoik replied. "He's not really thinking about escape; he's not really thinking at all. He wants to make a point, and he's willing to do it with innocent blood."

"Seriously, let me at him!" Scott insisted. "I can bring him down in…"

"One more word and you'll be suspended, Jorgenson," Stoik interrupted harshly. "There's a reason you weren't just handed your father's rank the minute you joined the force…"

"Sir?" Fisher lifted his hand, partly in salute and partly as though he were still in class. "What's that noise?"

Everyone paused and listened. At first, all they heard was Murdock's maniacal cackles; then a whistle came into audible range, rapidly climbing in volume and pitch.

"Sounds like a rocket," Tomah observed.

"Hey, nobody's supposed to go launching rockets in town!" Rowan protested.

"Yeah, that's very dangerous!"

Then the twins exchanged such evil glances that it was clear what they would be spending their weekend doing if they could only find a few spare rockets.

Suddenly something exploded on the roof. Shingles flew everywhere, and Murdock and a dark-swathed figure tumbled out into empty space.

The black figure writhed in the air, unfolding large bat wings and using its legs to grab Murdock in a kind of full nelson. With one hand it nimbly relieved him of his gun; the other arm was wrapped protectively around the boy, who looked terrified out of his mind but otherwise seemed to be intact.

Like a dark angel the figure swooped down over the cops. It opened its legs to drop Murdock practically right at Gob's mismatched feet and threw the gun at Stoik's feet. Then it shoved the boy into Fisher's arms, practically knocking the massive teen over, and with another explosion shot back into the sky. By the time the other cops recovered from the shellshock, the winged figure was gone.

The Night Fury. It never stole anything, never stayed in the light for long, and had done this kind of bizarre vigilante thing before.

* * *

The door opened briefly, disturbing the quiet of the forensics lab with the Chief's angry bellowing. Hiccup looked up to see who it was, and if they were dropping off evidence for analysis or picking up results; those were pretty much the only two reasons anyone came back to this tiny corner of the department.

It was Fisher, who quickly closed the door against the tirade. "Got an ID on those fingerprints yet?"

"Sure." Hiccup fetched the file out of the "Out" box and handed it to the much bulkier teen. "It's Baggett again."

"You'd think he would get into honest work."

Hiccup nodded at the door. "So what's he on about this time?"

"I, uh, wouldn't want to gossip…"

"Fisher."

Fisher sighed. "It's the Night Fury. For the second time today, making it the fifth time this week."

Then it was Hiccup's turn to sigh. "Let me guess: the department's all on his side wanting to gun this weredragon down along with all the others roaming the streets."

"About fifty-seven percent."

"Really, only fifty-seven?" That was a surprise.

"Maybe sixty; all the seniors who have personally had their egos bruised by this weredragon, and two-thirds of the cops our age."

Hiccup tilted his head. "But not you."

"I…" Fisher hesitated, looking carefully around the room as though making sure nobody would overhear him. Then he leaned closer. "I tried to motivate up some hatred for the Night Fury once, the day after his first appearance; I just couldn't sustain it. I kept hearing his voice… _warning_ me, _by name_ ,that I was in imminent danger from that Nadder. He _saved_ me." Fisher shook his head. "I owe him my life now; an Ingerman always honors his debts, even to something that doesn't look human. No, if the Night Fury dies, it won't be by my gun." As an afterthought he admitted, "I wouldn't mind arresting him, though; then I could ask him how he knew that _Ingerman_ was _my_ name. Besides, I think what he did last night counts as assaulting a police officer – I've got bruises all up and down my backside."

He was kidding for that second reason. Sort of. He probably did have bruises.

"How about the rest of the cops? The other forty to forty-three percent?"

"Oh; they think the Chief is…not _wrong_ in wanting to take out the Night Fury, but…premature. Night Fury can _fly_ , for Odin's sake; we're only equipped right now to handle weredragons on and under the ground, with some aquatic and grappling experience. Basically they want to take out the rest of the Helheim's-Gate organization first, _then_ go hunting Night Furies."

The door slammed open, startling both boys, and the Chief himself loomed in the frame. "Hiccup, to my office _now_." He thundered away, leaving the door swinging.

Fisher stared at the doorway. Then he looked at Hiccup. "What did you do now?"

Hiccup felt all the color leave his face. _He didn't notice when I disappeared for a week, a couple months back; he couldn't possibly be aware of my current nightlife._ The thought didn't do much to console him. He had to force his legs to follow his dad's trail, and consciously ignore the panicked voice in his head telling him to run out of the precinct as fast as he could go.

* * *

Hiccup fidgeted uncomfortably in one of the chairs before the massive desk. He didn't dare raise his eyes higher, from the nameplate to the vast man behind said desk, for fear that his eyes would betray him.

"This might come as a surprise to you, Hiccup, but you're not in trouble," Stoik said gruffly. "So you can stop slouching, it's unprofessional."

Hiccup couldn't seem to make himself uncurl all the way, but he got far enough up that he no longer looked ready to be whipped. _Not in trouble,_ he reminded himself with a deep breath, and he finally raised his eyes.

He was planning to look his father in the eye. His nerve broke at the last moment, and he stared at the big red beard. _Close enough_.

"It's time you got some field experience, Hiccup…"

"Dad…Sir…"

"…And this new case ought to play right into your strengths."

 _What do you know of my strengths?_ "What new case?"

"It's this Night Fury." At Hiccup's stricken look he snorted in exasperation. "Don't look at me like that – it has been brought to my attention that if he were truly a danger to humans he would have been striking _with_ the other dragons instead of joining the fight _against_ them. You're not going to be carried off. Probably."

 _Thanks, Dad, really reassuring there…_

"However, he's still a vigilante at best and a loose cannon at worst; we need to bring him in or bring him down. And that's where you come in."

"Me?" Hiccup squeaked.

"It's very simple. Observe this dragon however you can: photos, video and audio feeds, traces of DNA, anything we can ever get on this thing. Analyze him. Find a weakness we can exploit. Then I can send a properly prepared team after him, and it's one less worry."

Hiccup could imagine any number of objections; most of them simply couldn't be said. He went with the most basic. "You said yourself: at best, he's a vigilante. He strikes like one. Even if he's only a danger to lawbreakers…by the time I'm somewhere he would show up, I would also be somewhere that a dangerous criminal or several are as well. I know you want me to get some time out in the field, but throwing me on a gang's doorstep just seems…extreme."

Stoik sighed. "Which is why you're also getting a partner."

"Fisher?"

"He's taking over your lab duty. Wouldn't be much good in a Night Fury chase, anyway."

"Rowan? Tomah?" _Please not Scott…_

"I was thinking of someone who would take you, and your skills, seriously."

 _Definitely not Scott._ Unless the lout had somehow managed to convince the chief that he believed in his lab-rat cousin, which seemed unlikely. Scott wasn't that smart, and Stoik wasn't that dumb.

There was a sharp knock at the door.

"Come," Stoik called gruffly.

Astrid Hofferson stepped inside.

"Astrid, meet your new partner."

Hiccup's breath got lost somewhere. Astrid had stolen his heart years ago just by existing, but she also terrified him; he'd never spoken to her, short of – very recently – asking if she wanted coffee.

Astrid looked Hiccup over critically for a moment. Then she looked at Stoik. "Really."

"You will be taking him with you on the street. He needs the field experience; he's a bright boy, though, so you won't have to do much active teaching. Just let him watch you, let him ask his questions – and don't hesitate to use him if you think he can accomplish something." Stoik made a note on some papers and closed them up in a folder.

"Understood."

Stoik passed her the folder. "Feel free to take any case that doesn't interfere with your primary investigation."

Astrid took one look at the label and her eyes blazed up with excitement. "The Night Fury case?"

Stoik smiled. "Moving up in the world." Then he waved a hand in dismissal.

Hiccup and Astrid filed out.

As they walked back to the desks, Hiccup fidgeted uncomfortably. _I should say something._ Except he couldn't think of what to say – or how to say it. This was _Astrid_ : she didn't do small talk, at least not in the office. Professionalism was the key.

"So, um…"

Astrid silenced him with a viselike hand on his shoulder. "Let's get something clear: I'm not a babysitter," she said firmly. "Don't get in my way, don't tread on my heels, save all your questions for appropriate times and places – and don't wander off, because I won't be chasing you."

Hiccup's brain seemed to be malfunctioning due to Astrid _touching_ him; he half-frantically spouted the first thing that came into his head, which just happened to be, "Don't ask me to wrestle a Monstrous Nightmare and we'll call it good."

Astrid snorted and let go of his shoulder, casting a disdainful eye at his shoes. "When you show up for work tomorrow, wear running shoes. If we have to run, you'll be grateful." She returned to her desk and started reading the file.

Hiccup retreated to the forensics lab and heaved a sigh of relief. Astrid wasn't _happy_ to be his partner, but at least she wouldn't take out her fury on him. Unless he did something monumentally stupid.

* * *

"Sharpshot, I'm home," Hiccup called as he locked the door behind him.

A meow came from the living room. Sharpshot was under the coffee table, patented innocence in his big green eyes to convey that he had _not_ been busily distributing hair all over Hiccup's favorite chair.

"That face of yours might hold up in court, but I don't believe it for a second," Hiccup told him. He went to the kitchen and scooped some dry food into the cat bowl, and in an instant the cat was there to start emptying it again.

One could be forgiven for thinking that Sharpshot was a boring brown cat: he looked all-brown when he sat huddled on a windowsill or on the floor. Then he would roll over and splay his legs out, and surprise everyone with a chin, chest, and belly the color of old ivory. He was a crazy animal, and had a way of dashing all over the small apartment.

"I've been assigned to fieldwork."

An ear twitch.

"Astrid's my partner."

Another twitch.

"We're investigating my alter ego."

Sharpshot stopped eating and looked up.

"Yeah, I'm really looking forward to the day she learns that _I'm_ the Night Fury." Hiccup shook his head and sighed. "She'll probably shoot me. And then you'll be back on the streets, looking for some other sucker to hook your claws into."

Sharpshot sneezed and went back to eating.

"It's not all bad, this case," Hiccup mused. "I'll be able to run some analyses on myself, figure out what my strengths and weaknesses are…I just have to figure out how to do it without raising suspicions."

The truth, when it came right down to it, was that Hiccup knew almost nothing about his "alter ego." All the information he had was what he'd figured out by himself in what he ironically referred to as his Lost Week ("lost" because, when he returned, he found that nobody had missed him at all) and the subsequent nights on the rooftops. He knew that:

1 - He could switch back and forth between human and dragon at will,

2 - He was stronger, faster, and tougher-skinned as a dragon, and that seemed to have overflow back to his human form as well,

3 - His night vision was phenomenal and he had such keen hearing that a chirping cry could be used for echolocation; his sense of smell had improved, too,

4 - He had a strange reaction to a certain grass-like plant; it was like a strong dose of happy-juice,

5 - He could spit fireballs of incredible heat and force, and his jaws could distend for larger bursts,

6 - He had fully functional wings that folded seamlessly to his shoulders and ribcage when in human form (they took most of a week to reach a size that could support him in a glide, and still weren't yet large enough to _fly_ him anywhere for very long without periodic bursts of fire for extra lift).

The passive qualities were fine, but the transformation, functional wings, and fireballs bothered him when he really sat down to think about them. When those traits were forced into his body, the controls to use them were forced into his brain; there was no other explanation for how he was able to manipulate those new attachments, with or without practice. And there was no way to know what else had been downloaded into his mind, either. Instincts, reflexes, habits…

He tried hard not to think about his first meal in dragon form. A trout…that he'd swallowed whole, raw and still alive, before he'd had a chance to stop and think. Hiccup had been ravenous then, his stomach demanding that he fill it and fill it _now_ ; he regretted it later, when in a panic he'd forced himself back to human form and got indigestion with the blasted thing doing death throes in his stomach. He also tried _really_ hard not to think about the fact that, when he fell asleep in dragon form and was roused by hunger, while he was still half-asleep he would drag himself to his own scrap pile and eat the heads and guts that his fully-conscious _human_ mind hadn't been able to force down. He'd nearly thrown up the first morning that had happened, when he woke up all the way and realized what he'd done.

One time – _once_ – after he got back home he transformed in the bathroom and looked in the mirror to see exactly how far his jaws could distend. He scared the living daylights out of himself, not with how far his mouth could gape but with just what his expression was when he contorted the muscles of his face to do that: he looked ready to bite someone's head off, and the transformation had given him the teeth for the job.

Was the chief right? Was the Night Fury – was _Hiccup_ – a monster?

Nightmares were horribly common after that. They were always of the initial turning: the stabbing in his back, the fire in his blood – and worst of all, the demons flaying his mind with claws of fear and rage.

Hiccup would probably have gone crazy if he hadn't found Sharpshot just outside the apartment's parking garage, flashing passersby and trying to catch gnats or something with his paws. The stray had acted so loopy that Hiccup checked the plants around the garage to see if there was any catnip growing there (there wasn't), and then hauled him to the nearest vet (who gave him a clean bill of health). Nobody turned out to be missing a brown-and-gold tuxedo cat, and by then he'd gotten attached to the crazy thing, so he paid all the bills and now had a furry companion on the premises. A companion who, simply put, wouldn't allow him to brood all evening or all weekend – Sharpshot wasn't especially clingy, but he did occasionally demand attention by jumping down on his roommate's head or climbing up his leg.

He was a terrible little terror. Life was good.

* * *

"Listen, um…"

Astrid looked up, nearly making Hiccup lose both his concentration and the two takeout cups of coffee in his hands. He put the cups down quickly before he dropped them all over her computer, and struggled to compose his thoughts again.

"What?" Astrid sounded impatient.

"I just…you don't like dragging a partner around, I get that. _I_ don't like being short on information. So…please, could you keep me up to date on, on…" his mouth got jammed as his brain latched onto the word _date_ and started assigning a lot more meanings. He cringed.

"Like it or not, we're partners," she reminded him testily. "Of course you'll be in the loop for this investigation. You'll be involved in it."

 _Like I could forget._ Her phrasing left it open to question which of them she was referring to in regards to "liking it," and Hiccup was not going to ask for clarification or make a fool of himself insisting that it was no problem.

"I was actually talking about our relationship." Then Hiccup heard what he'd just said and, in a panic, started scrambling. "I mean, I don't – I won't play guessing games. If I do anything, _anything_ , to piss you off, please just tell me instead of leaving me to wonder about it for days on end; then I can apologize or explain or whatever I need to do to make it right again, and we can move on." Did that make it worse? Her borderline shocked expression offered no clues…he decided to quit while he was ahead.

Assuming he was ahead. But in any case, if he wasn't, there wasn't a thing he could say at that point that would make it any better and a very big number of comments that would make it worse.

Belatedly he thought to stick out his hand. "Deal?"

Astrid looked him over carefully, still wearing much the same expression. Then a corner of her mouth twisted up, and she stood to shake his hand. "Deal."

He'd offered his left hand, and she shook with her left hand. That meant her right was completely free to snap out and jab him in the shoulder while she had his arm immobilized.

"That was for asking in such an unprofessional manner." She settled back into her chair and lounged back. "One would think you were trying to ask me out."

Hiccup laughed – or tried to – and shook his head as he rubbed his shoulder. "If I were to try and ask you out, I would probably wind up unconscious at your feet," he admitted.

Astrid snorted slightly, the other side of her mouth curling. "And don't you forget it."

 _He'd_ meant he would have fainted. _She'd_ probably meant that she would have beat him to the ground. It didn't really matter, because the end result would have been the same.

Hiccup would love to take Astrid on a date. Trouble was, at the start of high school he'd had this extremely geeky thing going: he'd practically been a talking fishbone, and that in turn made him something of a bully magnet. Thanks to who his dad was, none of the damage to come his way had ever been permanent, and in fact he'd managed to bribe his way out of a few beatings by offering to do their homework for them (translation, dictating to them what to write; he'd pointed out that all the teachers would recognize his left-handed slant). He was just starting to get interested in girls, but none of them would look twice at him – unless he did something stupid and clumsy, and then they would laugh at him.

He'd mostly outgrown that now, but nobody would let him live it down – not even his dad – and so far no girl had turned around to see that he wasn't the skinny little weirdo anymore. Granted, he still tended to keep his head down and stay out of everyone's way; the habits that had taken root in his years attracting bullies were serving him well to hide his new wings.

"So," Hiccup said briskly, dragging his thoughts back to the reason for their partnership, "What's the plan for today?"

Astrid plucked a file off her desk and waved it at him. "Clarence Kent claims that Corbin Cavalier cobbled his copper collection."

Hiccup stared for a moment. Then his eyes narrowed and he held out his hand. "Let me see that."

Astrid burst out laughing. "Oh, you're too easy," she teased, offering the file.

He skimmed quickly through it. The man who'd reported the robbery really was named Clarence Kent, but Corbin's last name was Knight, not Cavalier. And the collection of trinkets he'd "cobbled" were different kinds of bronze, not pure copper.

 _I didn't even know Astrid had a sense of humor._


	2. Chapter 2

"Are you going to be this twitchy _all day_?" Astrid asked testily, drumming her fingers on the steering wheel.

Hiccup giggled sheepishly. "Um, yeah. I'm on street duty for the first time since I got my badge, I've had no combat training, and I…all right, I'm terrified of screwing up in front of you. I will probably be twitchy until further notice."

Astrid looked at Hiccup (who went white). "So what, part of it's me?"

"A _lot_ of it's you, and _keep your eyes on the road!_ "

Great. Her partner was a nervous passenger. She rolled her eyes back to the street. "I know what I'm doing."

" _I don't._ This is all foreign ground to me."

They drove in silence for a little while.

Actually, Astrid had had worse team members. After ten minutes Fisher had her looking for a muzzle, the twins had her looking for leashes – or straitjackets – and Scott had her looking for both. Hiccup was willing to follow her lead and was disinclined to take chances. He was also honest: he made sure she knew his weaknesses as well as his strengths before they even left the building.

She'd taken him to the shooting range before they hit the road, and after...demonstrating…how the scoring system worked, she gave him a gun and told him to "give it a shot." All right, she'd been trying to intimidate him a little: her accuracy percentage was well up in the nineties, all hitting the human cutout in the approximate location of the heart. He got the message, too – and then proceeded to shock her by firing his bullets right through the holes that her shots had left. Astrid hadn't believed it at first, and called up a new target. She had to concede his skill the second time, though, when he drilled all six shots right through the heart with bare millimeters to spare between them. If his accuracy percentage wasn't an even hundred, it was damned close; the boy could score headshots.

Astrid would gladly let Hiccup supply cover fire for her in a hostile situation. If that kind of skill could be transferred from a controlled environment to an uncontrolled one, he wouldn't accidentally shoot _her_.

"Do we have a game plan for catching the Night Fury?" Hiccup finally asked.

Astrid sighed. "Not really." Then she looked sharply at Hiccup. "I trust you have some bright ideas?"

Hiccup went absolutely rigid, staring out the windshield as though expecting to see Doom bearing down on them. With another sigh Astrid returned her eyes to the road. Presently, as nothing happened, he answered her question.

"Well, we obviously can't tackle him the way we tackle other weredragons."

"Obviously." Astrid was sorely tempted to look at Hiccup again, since it clearly freaked him out when she took her eyes off the road. She resisted, though. "He'll just fly out of any traps we set."

"Well, or simply avoid them." Hiccup shrugged. "He's intelligent, isn't he?"

Astrid almost looked at him again just on principle; there was something odd about the way he said that. Not wanting him to freeze up again before he answered her, though, she just cut her eyes at him. "You seem to think he wouldn't flap out of traps."

Hiccup smirked at her phrasing before sobering again. "It's…Fisher told me about the Night Fury's MO, and I thought it was…interesting."

Astrid stopped at a red light and looked at Hiccup. "Which part?"

Hiccup looked back. "The part where nobody has ever seen or heard him _fly_ _in_ from anywhere. He dive-bombs off of skyscrapers, and then shoots off in random directions that don't include back up. That's the act of a glider, not someone or something capable of true flight."

Astrid thought about that. He had a point; the Night Fury's so-called "flight path" always took the shape of an L. It wasn't really flying – just falling out of the sky, and then gliding to a safe place well away from where people were shooting.

"Green light," Hiccup added.

Automatically she put her foot on the gas pedal. "So about the only way we could trap the Night Fury would be to station guards on all the nearby rooftops, or set up a snare-launcher aimed at his turning point." Astrid contemplated that idea wistfully before shaking her head. "Not possible. We don't have the manpower or the equipment to pull either of those off; certainly not during the kind of situation he decides to show his face. Anything more useful to offer?"

"Did Fisher tell you about his first brush with the Night Fury?"

Astrid snorted. "Sure – he told everyone who would listen. I think he even wrote 'the Night Fury can talk and it knew my name' in his report to the chief. Why?"

"I was just thinking that if the Night Fury could talk – intelligently – and have respect and consideration for the police force, we might be able to bargain with him."

" _What?_ "

The car lurched into a parking space and slammed to a halt.

Hiccup gave himself a little shake. "Next time, _I'm_ driving." He took a deep breath. "But no, I'm not kidding. We know pathetically little about weredragons in general; I checked the records myself. If we learn things from the Night Fury that are effective against other dragons, we'll be able to stop the raids much faster and with fewer losses. If we can stop the raids easier, Helheim's Gate will either go away or send so many dragons that we can calculate their origin. If they leave, we're done; if we can find them, we can bring them down and _then_ we'll be done. Think of it: a time of relative peace, where the only criminals we have to bring down are humans of normal strength and speed."

Astrid looked askance at Hiccup. "We're supposed to bring down the Night Fury here."

"Yeah, I know, I'm just…I think we can convince the Night Fury to let us analyze him by offering a trade."

" _What trade?_ "

"Alliance. Legitimacy. Political asylum. Whatever term you prefer." Hiccup gestured earnestly. "If we really can use anything we learn against the other dragons, we can register him as a kind of informant or even legal backup. If the department acknowledges him as something like that, he might just walk right in with news for us someday."

Astrid stared at Hiccup in amazement. "You're naïve, you know that? Why would the department acknowledge him as anything other than a threat to be eliminated?"

"If the chief accepts it, the others will fall into line."

"So why would the chief accept it?"

Hiccup sighed. "He wouldn't be happy about it," he admitted. "But…he's not so stubborn that he'll just throw away a source of info."

Astrid decided that she would have an easier time getting behind this idea if Hiccup sounded less like he was praying about his dad's stubbornness issues. "We'll get back to that. How about the Night Fury? What makes you so sure _he'd_ go with it?"

Hiccup shrugged as broadly as the confines of the car would allow. "Put yourself in his skin. Everybody on both sides is shooting at him, and he doesn't want to join the dragons for some reason. Maybe he still considers himself human; maybe he just likes the underdogs. Regardless, if the humans are offering to _stop_ shooting at him in exchange for a little information…well, wouldn't you jump at the chance?"

" _I_ would be extremely suspicious. Where's my guarantee that the info I provide won't then be used against me? In fact, how would I know that I won't simply be shot after sharing?"

"Put yourself in his skin," Hiccup repeated with a sigh. "He's a weredragon, even if it's not one we really recognize. We _know_ he's armed with the most explosive, destructive firepower known to dragons, and he must have some pretty incredible senses to make those well-timed entrances. If you were endowed with powers like that, wouldn't you notice if the person you were talking to was about to pull out a weapon, and retaliate?"

Astrid conceded the point with a shrug and a noncommittal sound. She was sure enough of her skills _without_ dragon powers that she would bet her life on catching betrayal with time to react.

"So he wouldn't worry about being shot after he gives his information. As for the other…if he really, really thought that his information would be used against him, he would probably leave. Sure save us the trouble of keeping him in jail, and no wasted bullets."

There was just one more problem with this idea…

"How did you plan to contact him? Nobody knows where he lairs by day; there's no predicting when and where a Night Fury-attracting crime is going to take place, so there's no predicting when and where _he's_ going to show up."

Hiccup shrugged. "Well, that's why we're going to observe the Night Fury; maybe there's a way to get a message to him that doesn't require knowing where he is. Heck, if his hearing's good enough we could broadcast something on a frequency dogs can hear."

Astrid shook her head with a sigh. Then she smirked. "Hey, I've got an idea."

Hiccup eyed her warily. "If it involves shooting something that _has not acted against us_ , I'd rather pass."

"I'm not going to kill him! And yes, I read the report – I know trackers don't work." It had been tried before. Cops had successfully hit the Night Fury with bullets that sent out homing signals; the bullets were always found again, wiped clean and left in alleys within a block of the incident where he was shot with them. "I was thinking more like a message in a bottle. Well, in a bullet."

Hiccup paused. "You know…that could work. He cleans the bullets before he leaves them where there's even a chance of someone finding them, he would surely notice if one could open. You'd run the risk of his being resentful of you afterwards, though, whether he accepts the invite or not."

"Tough. He's the one playing hard-to-get." Astrid pulled back out onto the road.

"When we get back to headquarters I'll work on a hollow shell."

* * *

Operation Gun-Mail surpassed all expectations.

The Night Fury's next appearance was during a dragon raid. Hiccup had absolutely refused to leave headquarters while there were dragons charging around, and no amount of threatening could lodge him; so Astrid was the one lurking by the cars listening intently for the telltale scream, armed with a gun that looked a bit like a drastically-miniaturized rocket launcher – with just one shot.

The note stuffed in the shell was very simply worded: _I just want to talk. Meet me at 2100 hours in the old station on Fifth._ The "station" was a gas station that had been abandoned for years, so far out on the fringes that not even hoboes lurked there for fear of weredragons. It was isolated enough that the Night Fury would feel comfortable revealing himself, although Astrid refused to go there unarmed.

"I don't know this Night Fury. I don't know if he'll defend me or run for his life if other weredragons show up, and I want lethal force."

The raid had been in full swing for almost twenty minutes before Astrid heard the scream. She jumped up on the hood of the car she'd been hiding behind, bringing the gun up and releasing the safety. Then she waited for the explosion that marked the change in direction. There was no guarantee that he would come _this_ direction, of course – but Astrid preferred the act of pulling a trigger far more than sitting around waiting for sensor equipment to give her a reading, and would take the shot whenever it presented itself.

Luck, or the gods, were with her that night. When the dark shape caught wing on its own explosion, it shot practically right towards her – a massive humanoid silhouette with wings. Reflexively she brought her gun up, allowed for her target's speed and any wind resistance, and pulled the trigger.

The shadow screamed and veered off-kilter, one of its legs catching up as if in pain.

Astrid felt a surprising twinge of guilt at having wounded the beast – but also a sense of triumph that she'd successfully delivered her message, and relief that she'd hit exactly what she'd been aiming at. Or near-exactly. She'd been aiming for the middle of his left thigh as a safe spot, but couldn't tell by the shadow's movements if that was where she hit. All she was sure of was that _if_ she'd erred, it was low rather than high.

Several other officers, having heard the second scream and recognized "someone actually hit the Night Fury," took off in hot pursuit. Astrid couldn't bring herself to be worried about someone stealing her case, though – the Night Fury either had remarkable healing properties or enough sense to apply pressure to an open wound, because it never left a blood trail to follow.

* * *

The next morning Astrid was bubbling over with excitement as she rushed to her desk.

Astrid. The model of the cop's professional attitude.

Excited like a little kid who had just won the biggest prize at a carnival game.

Most of the senior officers shook their heads, thinking that it was because she'd wounded the Night Fury and perhaps had landed a tracker on it. They were sure she would erupt the minute she realized that the tracker hadn't worked, and were laying bets about if she would throw the tantrum at the office or at home (or anywhere in between that wasn't work and wasn't strictly private).

Astrid heard them discussing it and was amused at how they were half-right about her reasons.

Hiccup was already at their desk space, moving things around. He looked a little pale and seemed more withdrawn than usual, but Astrid was too interested in her success to think anything of it.

"I got him!" she announced, swiping one of the coffee cups off the desk and gulping half of it down. Then she grimaced at it slightly. "Too much cream."

Hiccup smiled wryly. "That one was mine." He nodded at the other cup, which was actually on the coaster by her computer. "I remember how you like your coffee."

"Oh never mind, I'll buy you another one." Swinging into her chair, she took the tops off both cups and topped Hiccup's coffee back up with her own before taking another drink.

"Really, coffee on you? Somebody's in a good mood; you're not usually…generous."

Astrid contemplated the cup. "Do you think he got it?"

"The message? I'm sure he did. Of course, you'll know for sure that he got it and understood if he shows up tonight at the designated time and place."

" _I'll_ know?" Not that Astrid had any objection to taking all the thunder for herself, but she and Hiccup were supposed to be a team. If she'd thought about the meeting tonight at all (and she hadn't), it was that she and her partner would meet the Night Fury together.

"I'm not in fighting condition, and the earthbound dragons terrify me. If other dragons do show up, especially if there are Monstrous Nightmares, you'd be babysitting me and we'd probably both be killed unless the Night Fury decided to step in."

Astrid paused and looked at Hiccup, finally noting the color of his face. He'd made a remark before about not wrestling a Nightmare, but she'd thought then that it was because of common sense: they could set themselves on fire. Now…she was beginning to think there was a hard-core phobia going on.

Which was odd.

"Just curious, why _especially_ Nightmares? I'm not arguing that they're the most horrible of the lot, but not by _that_ much."

"I…" Hiccup swallowed, his expression twisting into a bitter display of fear, loathing, and resentment. His next words were a mutter. "I'm not going to take it out on my partner."

Astrid cocked an eyebrow. "You're incapable of shocking or offending me. Whatever it is, just say it; get it out of your system."

Hiccup glared at her. Not like she was personally to blame for his problem; more like she was one of a much larger entity that was responsible. Then he shrugged out of his coat, swiveled towards her, and proceeded to roll up his sleeves as far as they would go and his pant legs to the knee.

She'd thought she couldn't be shocked. She was wrong.

She hadn't even known he _had_ scars.

A few were cuts; most were puncture wounds. Some were perfectly round, a straight stab, and others were more almond-shaped as though the claw that caused them had gone out a different angle than it had gone in. A few had a weird texture, like they'd been infected for a while before finally healing. And there were _so many_ of them.

"What on earth?" she gasped, raising her eyes to stare at his face.

Hiccup smirked a bit. Obviously he could tell that she had in fact been shocked. "And these are just the ones I _can_ show you. You'll have to take my word for the others, because I'm not stripping here."

" _You have more of them?_ " Astrid couldn't believe it. "How…what…"

"Monstrous Nightmare." Hiccup covered the scars again. "It took a week to recover from what he did to me. One. Whole. Week. When I couldn't come in to work for the pain of it."

"There was a week when you…" suddenly Astrid stopped, realizing why Hiccup glared at her a minute ago and why his face had been so resentful.

It was in her own half-finished question.

He'd vanished for a week, and she hadn't noticed. _Had anyone?_

"When?" she whispered guiltily.

Hiccup's expression relaxed. "Two months ago…almost three, now. And they still sometimes act up a bit – like right now there's one that's really sore…" he absently rubbed his thigh, "…so I can't run very well." Some of the resentment flickered in his eyes again, but he managed to keep it out of his voice – sort of – when he spoke again. "And to answer your other question, Gob and Fisher both noticed that I was gone, but they just assumed that my dad temporarily reassigned me somewhere."

Few noticed. Nobody missed him. Nobody cared.

Expendable.

No wonder he was so angry. And hurt.

"I…" Astrid paused. What on earth could she say? She couldn't defend herself not missing him: she didn't remember what _she'd_ been doing two to three months ago, that she'd been too busy to notice the presence or absence of a lab rat. She couldn't offer to "leave him home" on days when his scars caused him pain, because the chief would notice and be on _both_ their backs. Daddy was determined that his son get some field experience.

 _I understand?_ Understand _what_? Being overlooked? She never was. Being injured? Simply put, she'd never been injured so badly that she needed a week to recover; not since she was a little girl and sprained her wrist, and that didn't hold a candle to being worked over by weredragon claws.

Hiccup shrugged. "Could have been worse: he could have spewed fire all over me." He turned back to the computer.

The tension between them was thick and heavy. Astrid felt like she'd broken something, and she wasn't sure what. So she did the only thing she could think of to patch things: she drained her accidentally-purloined cup, and went to buy Hiccup a replacement coffee.

It took a few minutes of careful doctoring and tasting before she was sure she had it right.

Hiccup looked irritated at her attention-demanding jab, but his expression melted into pleased surprise when she waved the new cup in his face. "Thank you."

"Listen…" Astrid gently rubbed the place where her fist connected, "I can't leave you at the office while you're still my partner. But you just let me know if those injuries are bothering you in a way that impedes field work, and I'll let you wait in the car. Just don't make things up to get out of active participation, all right? Not wanting to leave the lab doesn't give you the right to lie."

Hiccup smiled. "Thanks. And don't worry, I wouldn't lie to you about my injuries."

It was what Astrid had hoped to hear – and yet the tension was only weakened, not broken. A few minutes later while reviewing some of the cases on file, she realized why.

 _I wouldn't lie to you about my injuries_ was itself a lie – though not one of his usual terribly-obvious lies. She actually believed he wouldn't make up a painful old injury just to get out of field duty, so _that_ was true…but he would tell other lies about what had happened to him.

The flash of clarity was blinding: _he already had._ Some of the marks on him looked more recent than almost-three-months – in fact, the ones that she'd thought were infected were actually _almost new_.

But he'd been telling the truth about being hurt badly enough by a Monstrous Nightmare that he was laid up for a week, she was sure of it…

 _Wait a minute, he never actually said "A Nightmare put these marks on me." He implied, and I assumed._ She'd been too shocked by the scars, and too guilty that she hadn't missed him, to really think about what he was telling her.

She almost said something. She almost turned in her seat, wrapped her hands around Hiccup's neck, and demanded that he tell her what _exactly_ the Nightmare had done that forced him to spend a week recuperating.

For the first time in her life, her nerve failed her _._ The bitter expression that had been the first answer to _"why especially Monstrous Nightmares"_ was burned into her mind. He was _not_ ready to talk about whatever had happened in that week – seven days when the entire force demonstrated for him that he was completely expendable.

Something occurred to her – something she'd seen in Hiccup's profile and thought odd, and had meant to ask about but never quite got around to it. She called it up on her monitor and read it again – the whole profile this time, not just the highlights.

He'd had hardly anything, good or bad, attached to his name right up until…two and three-quarters months ago. Then – well, whoever wrote the profile noticed his absence: he had a work week labelled AWOL. Then he returned to the forensics lab…and turned into a reclusive workaholic, cracking cold cases by analyzing data.

Staring at her partner's history in black and white, thinking about that hurt resentment, Astrid knew what was going on: Hiccup had taken a terrible blow to his pride and was now trying to build himself back up and prove that he was a credit to the force. But it was a Sisyphean task – how many cases, cold or current, did he have to solve to prove anything? Especially with the general attitude this force had about forensics…he could be working for the rest of his life and never be acknowledged, forever unsung.

 _No, I won't press him for answers about that Monstrous Nightmare. I'll value what he offers, and_ show _him I value his contributions, and help him stop this endless pursuit of justification._ Then _I'll demand truthful answers about those scars._

"See anything interesting?"

Astrid jumped slightly and looked at Hiccup, who was watching her intently. Words tumbled over themselves in their haste to get to her mouth, but she firmly kept silent; she wasn't going to apologize for, or justify, wanting to know more about her partner, and she _certainly_ wasn't going to babble like an idiot. She considered – briefly – telling him that she found him valuable, but the words were so _odd_ that she couldn't imagine what he would think.

He'd asked a question, right? Was it rhetorical or did he expect a reply? She couldn't remember exactly what the question was, only the ironic and self-deprecating tone.

Had he started self-pitying? The wuss.

"I'd tell you exactly what I think," she finally replied, a little chill but not _altogether_ unkindly, "But I know what your answer would be. 'Talk is cheap, you'll say anything to further the cause whether you believe it or not…' No, my words will keep until you're ready to really listen."

Hiccup didn't quite gape, but his eyes got huge. Then he smirked. "I do _not_ sound like that."

Finally, the tension was broken.


	3. Chapter 3

Astrid wondered aloud at one point, before they clocked out for the day, if she should record this meeting for posterity. Or something like that. Hiccup missed the end of the sentence because his first response was panic: a later playback of any such recording would instantly betray him, if overheard by anyone who knew him and wasn't expecting the Night Fury to be capable of speech. He'd been afraid to argue too hard against the idea, however, because that would be suspicious – she was already wondering if _all_ his scars had been from the Nightmare attack, he could tell (and she was right: the only ones actually from said attack were all on his back, and the rest were bullet and spike wounds from his misadventures as Night Fury).

After he got home he did something he'd vowed never to do again: he looked at his dragon face in the bathroom mirror. He talked to himself a little, first to establish just how much like himself he actually sounded when in dragon form and then to see if he could distort it any further. What worked the best, with the least effort and presumably while still remaining perfectly comprehensible, was to hold a low burn in his mouth; readying a plasma burst without ever firing it. It made his mouth glow a nearly-blinding purple-blue, but there was just no help for that. Maybe she should be a little scared of him, seeing as he was a lot scared of himself.

One thing was for sure: she wouldn't recognize his face. Besides the distortion to his features caused by the shift and the low burn, he was also going to wear the lightly-armored cowl that he'd made back when he first realized people would be shooting at him. It deflected anything aimed at his face, protected his head and neck in the event of a crash, and completely covered his hair (which, for some reason, was completely normal even when he transformed).

* * *

What Hiccup had told Astrid that first day wasn't accurate anymore: he actually _could_ fly now. He only used the old MO out of habit – always on the alert for anyone who might have realized his pattern, and ready to wing away if they showed any sign of trying to strike. He knew exactly how long it would take him to fly from the roof of his apartment to the old gas station, and waited to shift and take off until exactly that long before nine o'-clock.

As he flew, he thought about this upcoming meeting and wondered what he was going to say. He hadn't discussed with Astrid how they were going to "convince the Night Fury to let them study him," because he didn't want there to be any overlaps between her two conversations: if he responded to something a certain way as Hiccup, and then responded the same way to the same point as Night Fury, surely even Scott would think it suspicious. That meant, though, that he didn't have any idea what direction this chat would take.

 _I guess I'll just have to…_ he grinned… _wing it._

And there she was, perched on the hood of her car; he could hear her tapping the bumper impatiently with her foot. He wasn't even late: she'd been early, possibly by as much as ten minutes. Certainly she'd had enough time to set up a lamp, so that she could illuminate the parking lot without draining her car batteries. Her gun was in her hand, ready to fire at anything dumb enough to shove a heavily-toothed face into the light. There was no recording device in sight, but there probably was a receiver on her somewhere.

Hiccup smirked; Astrid was being smart enough to not look directly at the light as she scanned the area, but she wasn't looking behind her at all. The bulk of her car was between her and anything that might come up behind her, after all, and she would hear it before it reached her. He seriously considered, and regretfully rejected, springing down upon her from over the car and taking her gun: no matter how fun that might be, it wouldn't help his relations with her. No, he would do this in a calmer fashion.

She noticed him glide silently over her head, at least; he saw her lift her gun, out the corner of his eye. Thankfully she didn't pull the trigger, but her eyes got massive.

Hiccup landed at the edge of the lamp's glow, carefully favoring his left leg, and looked up sardonically as he readied his "burn voice." Before he could say a word, however, Astrid let out an incredulous exclamation as she waved over her shoulder with her empty left hand.

"I thought you couldn't fly!"

Hiccup shrugged. " **Whoever told you that was right about three months ago. It took a couple weeks for my wings to be long enough and another couple weeks to be strong enough**."

"You're still dropping off roofs…and then using that explosion to…"

" **Habit, mostly. And if people get used to that and make their traps accordingly, they'll wonder what went wrong when I evade capture. So, that was moderately more entertaining than a bullet with a homing signal; what do you want, and can we discuss it without the gun? Or are you actually going to try and arrest me?** " The idea was kind of funny; she couldn't tackle him fast enough, and he'd be back in the night sky before she could think to shoot him for resisting arrest.

Astrid didn't move. "You have your firepower, I have mine. Fair's fair. And no, I'm not going to arrest you. Yet. My naïve, idealistic partner suggested that instead of clipping your wings we pick your brain."

Fortunately Hiccup had the sense to throw his head back before the laugh exploded out of him, because with Burn Voice active it was accompanied by an actual blast. Containing his mirth with an effort, he looked back at Astrid. " **He said that?** "

Astrid looked half-convinced that her heart had stopped. _And_ like she wanted to shoot the Night Fury. She managed to contain herself, though, and after a moment forced herself to speak again. "He _said_ that you can tell us about the weredragons' weaknesses. That with your _help_ we can shut down Helheim's Gate for good."

Hiccup cocked his head. " **You don't sound convinced.** "

"Why would you want to betray your own side?" There seemed about to be more, but Hiccup interrupted in surprise.

" **What are you talking about? The first definition of** _ **betrayal**_ **is 'an act of treason,' and the second is 'an act of disloyalty or unfaithfulness'; who do you think has my loyalty, that I would be betraying them by helping you?** "

Astrid gaped for a moment, incredulous. When she spoke again, it was with her best _talking-to-idiots_ voice. "Um, the people who _created_ you?"

" **I was** _ **created**_ **as a normal human almost twenty years ago by my mother and father. Both human; neither with any affiliation to Helheim's Gate that I know of, if that's where you're going with this.** "

Astrid's fingers flexed on the gun like she was considering a shot. "All right, then, who gave you those wings and scales? That firepower?"

Hiccup spread his hands. " **Think about that seriously, would you? Helheim's Gate hasn't changed its MO in at least thirty years; when they sent dragons to raid Berk, it was always** _ **at least**_ **three per species, and they** _ **always**_ **had the same attack pattern. If I were from Helheim's Gate, there would be at least two others just like me and they would be doing the same thing I've been doing the past two months. Which you would have heard about, since you're investigating me and would need all pertinent information to…** " he smirked, " **…bring me down.** "

Astrid frowned. He was right and she knew it, but didn't want to admit it. "So…you're claiming that your powers have nothing to do with Helheim's Gate."

Hiccup sighed – a strange sound with Burn Voice, like a whistle in a tunnel. " **I'm** _ **claiming**_ **that I'm not affiliated with Helheim's Gate. I'm** _ **claiming**_ **that one of their weredragons created me by accident, and I'm** _ **claiming**_ **that they don't even know I exist.** "

"How could you have been created by _accident_?" She didn't believe that, he could tell.

" **I know there have been people who were merely scratched by a weredragon, and died.** " Hiccup showed Astrid his hands. " **Look at my claws. Look at my scales. Then, when you get back to the precinct, look at the photos of the victims. According to all available statistics, I should be almost three months dead right now; by some twist of fate,** " his lip curled, " **My body successfully adapted to a venom that has killed at least twenty people in the last eighteen months.** "

Astrid paused, her gaze going between his hands and his eyes. "How could that be?"

" **How should I know? You cops are the ones who can gain instant, legal access to lab equipment. In case you haven't noticed, I'm a wanted man.** "

Astrid made a face but didn't otherwise comment.

" **You're analyzing weredragon carcasses to learn what makes them tick; when I'm sure I can trust you, I'll let you take a blood sample and you can analyze it to find out what made me different from the ones who died.** "

"You don't trust me?"

" **You're the one still aiming a gun at me – and simply put, you've made it abundantly clear that this is a temporary ceasefire. I don't have reason to trust you with my flesh. In the meantime…you want me to give you information to stop the weredragons.** " Hiccup shrugged. " _ **They are not my people**_ **, and to prove it I'll gladly hand out a little – though I have to warn you, I don't know how much of what I learned about myself in the past months is transferrable to other dragons.** "

Astrid… _perked up_ was the wrong term, but she suddenly looked much more alert and intense. "Go on."

" **Sound.** "

She scowled. "We knew that already."

" **O ye of little faith. Did you know that the** _ **right**_ **sound can disable weredragons, rather than just disorient them? Just play back a corrupted recording of their own cry – that would work on all of them, though best on the breed whose voice you used. I found that out the hard way, screaming at some other dragons in a tunnel; the echoes had them crashing into each other on the way out, and I nearly passed out.** " Hiccup shrugged. " **You certainly don't have to take my word for it, of course. You don't know the workings of my mind well enough to accept my educated guesses on faith. Try it out – or suggest someone else try it. See for yourself.** " He turned – not far enough to _turn his back_ on Astrid, but enough away that he was clearly about to leave – and opened his wings.

"So do I shoot you again, or would you like to prearrange a time and place when we can meet?"

And paused, readying his Burn Voice again. " **I would rather not be shot again: I've had enough of being shot** _ **at**_ **to last several lifetimes.** " He thought for a moment. " **As reluctant as I am to let you pick the second meeting place too, where would you feel comfortable enough to not bring your gun?** "

Astrid smirked. "You're not getting me unarmed, ever. And my partner picked this meeting place, not me; if I had my way, we'd be having this conversation at the used-car lot. In daylight."

It was a near thing, but Hiccup didn't laugh with Burn Voice again. " **I wouldn't have showed if you'd wanted a day meeting, so at least your partner had that right; the darkness is my shield. So. The used-car lot, say…a week from now; that ought to give you time to test the sound thing. Twenty-one-hundred hours again?** "

Astrid let out a harsh sigh of frustration. "Fine…"

Before she could think of anything else to delay his departure, Hiccup sprang into the sky and vanished from her circle of light. Then, remembering the most important thing, he circled back around and landed on the trunk of her car.

Astrid had gone to turn off the lamp, and was at the moment temporarily night-blind. She certainly hadn't expected him to return, and was blinking at the shadows in surprise and a little fear.

" **One more thing. If I see, hear, or scent anyone other than you around, I won't make my appearance – and don't think my senses wouldn't pick up a stranger from twenty yards off, even in the dark. You and me, and that's it.** " He left again before she could regroup enough to agree or disagree.

 _Coffee's on me in the morning, because Astrid is going to be pissed._

* * *

Everyone, including some of the senior officers, was giving Astrid's desk a wide berth the next morning _._ Scott was sulking at his desk, sporting the beginnings of a bruise that had not been on his jaw yesterday. Rowan and Tomah paused in their typical arm-wrestling over their own desk duty to stare at Hiccup's burden of breakfast rolls and coffee for two, with expressions that seemed to say _wow, there's someone more insane than we are_.

Hiccup had been right. Astrid was pissed. If even the twins didn't want to risk her wrath…

Knowing that she wasn't mad at "Hiccup" didn't help matters much, because he knew she was mad at "Night Fury." As he approached, he went over and over last night's meeting and reminded himself that nothing had happened that could be traced back to him.

Astrid hadn't noticed Hiccup's approach. She was wearing a discreet set of headphones, and all of her attention was on the computer screen. She wasn't actually _angry_ : that was her look of intense concentration, which could easily turn to rage if she was interrupted but in itself wasn't dangerous.

Very, very carefully Hiccup edged around the desks and looked over her shoulder. It was a computer program they used when trying to identify a person's voice through a distorter; Astrid seemed to be repurposing it, trying to create a sound.

Eventually she registered his presence and turned, pulling the headphones off her own ears and shoving them over his without even a _good morning_. "Does this sound like a Deadly Nadder to you?" she asked, clicking the Play button.

Hiccup could have answered that question without using the headphones: thanks to the dragon genes, his hearing was that good. But that would have raised suspicions, so he clenched his back teeth and endured the grating, synthesized sound being poured straight into his ears. Fortunately, whatever it was about corrupted playbacks that disabled dragons, it didn't happen as quickly in human form.

"Pitch could be a little lower here and here," he got out, carefully reaching out one of the coffee cups to point at the lines in question. Then when Astrid relieved him of the cup he quickly added, "And that one's mine, by the way."

Astrid put the cup on the desk, carefully away from the keyboard and files, and took the headphones back. "Did I get rid of the flat spot in the middle?" Noticing the rolls, she snatched one and ripped off a chunk in her teeth.

Hiccup looked away from her mouth. "There was a flat spot?"

"Mmhmm…" she swallowed. "It sounded more like a quack than a squawk. Why are Nadders so…parroty, anyway?"

"Asking the wrong guy." Hiccup took a careful bite of his own roll, chewed for a moment, and added with a smirk, "Could be just to annoy you."

"Ha. Parrots don't annoy me – donkeys do." Astrid relieved Hiccup of her coffee. "Bipedal, big-mouthed donkeys with nosy noses…"

"I thought I noticed a certain swelling on Scott's jaw; I didn't want to stop and stare, since he seemed touchy about it and he's much bigger than me."

Astrid's lip curled in a self-satisfied smirk around a delicate sip of coffee. "How'd he salvage his shirt?"

"What about his shirt? It looked fine…" Hiccup reflected on the memory; there had been a scent of moisture about his cousin, and his shirt had been more wrinkled than usual. "I think he'd soaked it in the john, and wrung it out again as best he could before putting it back on."

Astrid nearly purred. "He spilled coffee on it. Accidentally."

"Mm." Hiccup could see it all too clearly. Scott had tried to hit on Astrid – offering her coffee, merely slurping his own, it didn't matter. The end result would have been the same: her fist, in its path to his face, would have overturned the cup all over him. "Are you sure Scott won't report you?"

"And say what? That he got his face handed to him by a girl?" She took another swig. "Even if he did report me, I would then report _his_ inappropriate office behavior of flirting on duty and disrupting everyone else's concentration; I might get a reprimand, but he'd get worse. And he knows I would counter-report."

Hiccup shrugged. "If you say so; in fact, I'm a little surprised you haven't already reported him anyway."

Astrid played with her roll. "Don't think I didn't consider it. But I…regrettably…concluded that I'd punished him enough, considering we were both on duty, and that setting my work aside to report him would be giving him more attention than he was worth." Then she favored him a curious look. "Why are we talking about this, anyway?"

"Because you started it by referencing a certain donkey we both are unfortunate enough to know?" Hiccup teased – before suddenly thinking of what she might have noticed. For a moment his face froze; then, affecting a look of curiosity, he refocused on the computer. "But, since we've returned to the original topic, why are you trying to replicate a Nadder cry anyway?"

In a way, that would have been the biggest clue of all: if he didn't need to ask the question.

"Something the Night Fury said last night."

"Oh?"

"If he's to be believed – and if he's right; he as good as admitted he didn't actually _know_ – playing back a slightly-off dragon cry would knock out any weredragon that heard it." Astrid tapped the computer screen. "If I can get this right, we can give it to somebody on dragon-hunting duty and see what happens on the next raid."

Hiccup was pretty sure that was an exaggeration of what he'd said – but, unable to think of a way to correct Astrid without giving himself away, he let it be. "Scott would at least accept anything you gave him, and might even use it; the twins are crazy enough that they might try it if you promised 'insane' results. So, Night Fury…what else did he say?"

Astrid sighed. Heavily. "Loosely translated, he was willing to accept your olive branch – but he didn't trust _me_ enough to shake on it."

"I'm guessing the trust issue went both ways."

The growl was answer enough.

"You don't really think he's with Helheim's Gate, do you?" That was a dangerous point to push, he was sure…

Astrid clicked a few keys – and a moment later, a message with an audio file appeared on Hiccup's screen. "You tell me. About one and a quarter minutes in, we get into that." She offered him her headphones again.

 _So she_ was _recording it._ Hiccup shrugged slightly and, setting up the headphones and bracing himself for his own distorted voice, played the conversation back. _Wow, I sound really weird with Burn Voice…_

Talking about time had been a risk, he decided. _Three months ago_ could all too easily have been a tip-off, and so could the vague reference to his age. He hoped that wouldn't come back to bite him later; at least, not until people were willing to accept Night Fury as a legitimate informant.

After the recording was done he felt like he should say something. "Huh. I wonder which weredragon 'accidentally' created him."

"Does it matter?"

"Probably not…" Hiccup returned the headphones. "Are you…giving this information to the chief?"

Astrid looked sideways at Hiccup. "Yes. _After_ this little sonic toy of mine has been field tested. 'Look, Sir, Night Fury suggested on this evening that we use the weredragons' own voices against them; I tried it and…' whatever the result ultimately is. _If_ the outcome is favorable at all, then the next time Night Fury gives us a weapon suggestion we'll ask permission before we try it."

That was unexpectedly reasonable. Hiccup nodded, encouraged. "You might want to…corrupt the part with the…plasma blast. Or something. Don't want the chief thinking this guy attacked you when he didn't."

Astrid looked full-on at Hiccup. "How do you know he didn't?"

Hiccup was ready for that one. "I'd have heard about it, either straight from you or from someone who heard you ranting about it."

Astrid smirked slightly, wordlessly acknowledging that she would not have kept silent about a direct attack. Then she sobered. "By the way, about this venom thing…"

"Oh, yeah…the other victims. I've seen the autopsies…it's not pretty."

"Can you call up the pictures?"

"Not readily – from here," Hiccup shoved his chair back, "But the files are saved on my lab computer. If you would come with me?"

* * *

Hiccup's working theory about the venom – even before he was attacked – had been that it was a failed mutagenic cocktail that Helheim's Gate had chosen to use as a toxin rather than outright discard: it was just too much of a coincidence that _all_ of the ones to be poisoned by it sprouted black scales, claws, and sturdy membranes, twisting into half-recognizable-human freaks of nature that couldn't even be called weredragons.

Astrid only half-listened to Hiccup's rambling (and carefully edited) theories as she looked at the pictures, tight-lipped and just a bit pale. He couldn't fairly blame her: the victims died when their throats and chests exploded with their own plasma fire. They all looked like they'd tried to swallow live grenades.

"These arms do look like Night Fury's," she eventually admitted. "Except they have the regular sort of wings."

Even after having his theory confirmed with his own body, he didn't know why he'd survived with his sanity…as mostly intact as it was. Or why his wings were sprouting from his back. Or why he could hide what he was.

"Wonder why his are different? Why _he's_ so different?"

Hiccup shrugged. "Maybe when you've earned his trust, he'll let you examine him more closely."

Then he had to turn away quickly, his face turning bright red at the thought of Astrid running her hands over his back. Fortunately the object of his fantasies didn't even notice that he was having a freakout.


	4. Chapter 4

Deadly Nadders were jumping on vehicles, stationary and motionless. Gronkles were ramming through anything that wasn't moving – and even some things that were. Hideous Zipplebacks were rolling down the street as flaming wheels. Monstrous Nightmares were climbing on walls, dripping fire back to the streets below.

Just another raid. Until the twins turned on an unusual siren.

When Chief Stoik first heard the mechanical Nadder squawk on a loop, out-shouting the other sirens, his first response was to look for the Thorstons' shared patrol car. He wanted to pull them over and demand they turn the blasted thing off, lecture them about regulations, and interrogate them on how they'd manage to fit a recording into their siren.

His second response was, uncharacteristically enough, to stop and stare at the weredragons. Nightmares were falling off walls, Gronkles were smacking into walls, and Zipplebacks were getting tangled up in each other. All of them were beating as hasty a retreat as they could, which wasn't as hasty as usual. And the Nadders? They collapsed wherever they happened to be, wing-arms wrapped tightly over heads, and writhed in agony. They were completely defenseless when the cops rushed them and, depending on the officer, shot them point-blank or took them captive.

Then Stoik was still looking for the twins – but behind his angry countenance he had a different interrogation for them. The dragons had _never_ done anything like that before, and the only unusual variable he knew of was that siren.

* * *

When Astrid and Hiccup were called to Stoik's office the next morning, there wasn't much doubt in either of their minds that he'd learned of the siren and gotten out of the twins just who had given it to them. The only question now was if this interview would be positive or negative.

"I think we _are_ going to be in trouble," Hiccup said anxiously, wringing his hands. "I mean, even if that siren did what we thought it would do, it wasn't something we were ever told to build."

Astrid shrugged. "As tech-savvy as you are, building that contraption didn't take much time from our investigation. And it _was_ beneficial." She still had trouble believing that, but it was all over the office when they first walked in the door: the dragon-call siren had drastically increased the number of casualties on the side of the weredragons, and significantly reduced the injuries on their own side.

Tomah and Rowan had been thrilled. As predicted.

"We should make a few more of those, with other cries," Hiccup mused. "If we only use one voice, eventually Helheim's Gate will stop sending that particular weredragon and possibly create new and deadlier species to take its place."

Astrid thought about that and decided Hiccup had a point. The force knew the traditional four and were familiar with their attack patterns, and planned their own attack formations accordingly to reduce damages; a new "species" with a new attack style would send Berk's property damage and casualty rating back up, as the force wasted time trying to find counters.

There wasn't time to discuss the topic further, though, before they had to enter the chief's office.

Chief Haddock didn't keep them waiting, and didn't mince words. "The Thorstons have explained to me that their non-regulation siren was constructed and installed by you two, for the express purpose of disabling weredragons." He glowered fiercely at both of them, leaving it open to question whether he approved or disapproved.

Astrid nodded. "Hiccup built the thing during his off hours and fitted it to their squad car yesterday. I programmed the Nadder voice; there weren't any recordings available – that we could access without having to explain ourselves – and of the two of us I was the only one who had ever heard a Deadly Nadder."

Hiccup cringed.

Astrid was just making a mental note to ask him later what she said that he thought was wrong when the chief leaned forwards, his eyes narrowing. "Why was it so important that you not explain yourselves to your superiors?"

 _Oh – ack._ That was stupid. She'd just assumed… "Didn't Rowan and Tomah tell you what we said when we offered them the new siren?" she asked cautiously.

"They _said_ that you claimed the effects on attacking weredragons might be…unpredictable. I couldn't believe it. A device as likely to backfire as to be truly useful, and you give it to the two loosest cannons on the force?"

Astrid held at attention and kept her features composed, but inside she was cringing as much as Hiccup had been a moment ago – if not more. Giving the siren to Rowan and Tomah had been _her_ decision, because she hadn't wanted to inflate Scott's already-large ego by giving him the attention. "Actually, sir, Hiccup ran the numbers and was far better than half-sure the corrupted playback would have the desired effect. Everything we gave the twins about 'unpredictability' was a bribe."

One of those formidable red eyebrows lifted. "…A bribe."

"Russian Roulette with a new toy is just the thing to attract the twins' attention," Hiccup put in. "Sweetening the original deal, as it were."

The stony gaze slid to Hiccup. "And what was 'the original deal'?"

Hiccup didn't cringe again, but it was a near thing. "That was the part they _should_ have mentioned. We couldn't give it to anyone else: only they were, um, innovative enough to accept this completely new and still potentially risky technique."

The chief snorted. "Reckless and crazy enough, you mean."

"It did work, though."

"Right." He rubbed his forehead. "Now explain to me why I shouldn't dock both your salaries for letting this research and experimentation distract you from your original case?"

Astrid stepped in before Hiccup could get out more than a brief stuttered noise, and dove straight off the deep end. _What's that expression – in for a penny, in for a pound?_ "Actually, the Night Fury told us himself that distorted dragon cries would have that effect."

Hard to tell if that spastic twitch of Hiccup's was another cringe or if he was bracing for a coming apocalypse. If it was an explosion he was expecting, amazingly, he didn't get it – though Chief Haddock went extremely still and stared at them both.

For a long moment there was silence, as Astrid turned slightly and favored Hiccup with a look that promised retribution if he started babbling and ruined this moment. Then she withdrew an iPad from her pocket and placed it lightly on the chief's desk.

"If you would push play, sir, you'll hear the entire interview." Well, not the _entire_ interview: Astrid had cut her unprofessional, undignified response to the Night Fury's entrance, and after much consideration had also removed his explosive laugh. "And, if I might be so bold as to remind you, our mission was first and foremost to _observe_ the Night Fury. I was given to understand that bringing him down would come later, when we better understood his powers."

The chief muttered something ominous into his beard – and pushed Play.

Astrid flinched a time or two at her own attitude in the recording. Had she really sounded that…snarky? Treating the interrogation subject like he was stupid wasn't any more professional than the shocked and indignant proclamation about his ability to fly. Not to mention there were several points where she sounded on the edge of losing her temper; also a no-no in her line of work.

 _Not my fault, the Night Fury was determined to punch my buttons._ As an excuse, that was pretty lame; she resolved on the spot that if the chief called her on the attitude, she would simply agree to do better and not defend the lapses.

When the recording ended there was silence again for a moment. Then the chief looked at Hiccup. "I notice I didn't hear your voice at any point in that."

Astrid froze. She was done – any minute now the father would break down the son and it would be out that she'd left her partner behind on this one. The case would be taken away, she'd be demoted or suspended…

"Well, of course not," Hiccup replied smoothly. "Astrid wanted to handle the interrogation part herself, seeing as I had no practical experience in the matter and would very likely only manage to anger the Night Fury into incinerating me. Seems I have a way of provoking people."

Astrid wanted to snort. That was an understatement – although it was also a clever way of explaining why he didn't speak in the recording. As long as the next question wasn't…

"There is that," Stoik allowed. Then he glowered at Hiccup again. "I trust you were _there_ , regardless?"

And her luck just couldn't be that good. Here it comes…

"Of course I was; Astrid was in my sight the whole time, and I was ready the whole time with cover fire. Berk City Police Department frowns on its officers going into potentially hostile environments without backup, and I would never let a partner of mine face such a situation alone."

Astrid wanted to gape. Lab rat Hiccup Haddock, the worst liar in the department, had somehow managed to deliver that massive whopper like it was nothing but the truth.

What was going on here?

The chief nodded. "Now then, when was this recording taken?"

Still shell-shocked by the bizarre deviation in an otherwise perfectly straightforward nerd, Astrid fought her attention back to the task at hand. "Um…three…no, four days ago."

"And when were you planning to inform me of this meeting?"

"It was Hiccup's idea to withhold our progress until we'd confirmed for ourselves that the Night Fury's suggestion about handling the other dragons was sound."

Hiccup glared indignantly – and a little fearfully – at Astrid.

 _What? Don't pretend you weren't already considering that. I'm not unobservant or stupid, and that was pretty much the only reason I suggested it myself._ It was strange that he would care so much about the fate of some weredragon, but it was obvious that he did care about this one.

And he wasn't ready to answer the question of _why_ , at least not out loud to anyone else, she realized in the next instant. Quickly, with the intent of forestalling the variation on _why does his integrity as an informant matter so much to you_ , she added, "And with your permission, I should like to continue these meetings with the Night Fury and gather as much information as possible."

The chief had just taken a breath, possibly to ask the unanswerable question; he let it out in a heavy sigh and rubbed his brow again. "Why not? If these meetings turn into regular occurrences, we might be able to trap him at one. And any information that makes these weredragon attacks easier to stop, is good information."

Astrid took a deep breath of her own. "There's just one more thing, Chief…"

"What now?"

"After the time and place for the next meeting was established, he came back for a moment; this isn't on the recording because I'd already turned it off – I thought we were done."

The chief looked sharply at Astrid. "And?"

"I don't know if his senses are as good as he claimed they are or if he was exaggerating for effect, but he basically said that he would notice if the second chat group was bigger than the first and wouldn't come in if it was. It has to be just me…and Hiccup."

He didn't like that, she could tell.

Hiccup cleared his throat. "Might be easier to get his guard down if it's always the exact same face that he's talking to every meeting – building trust, you know."

Astrid nodded. "And if he does have a way of counting heads…if we play the party-size game his way enough times, he'll eventually trust that the party _won't_ get any bigger and stop checking. Then we'd have him."

The chief buried his face in his hands. "Fine…I'll make a note of it. _You_ make a note to tell me when you think we have him. We're done here – get back to work."

Astrid and Hiccup filed out silently. Then, halfway back to their desks…

"That went rather well, actually," Hiccup said softly.

Astrid wanted to deck him, just on principle. "Chief looked dyspeptic, and like he wanted to break something, and you are _not_ going to convince me that he's one-hundred percent behind this idea of yours."

Hiccup shrugged. "He didn't start shouting; we're not suspended, we still have our full salaries, and we're still on the case. Compared to a public dressing-down, that was phenomenal."

 _Public dressing-down?_ The memory rose unbidden – several of them – and Astrid flushed slightly. Hiccup had been berated in just that fashion, many times before…before he vanished for that week. Thinking back on the lectures now, she found herself embarrassed for him.

"Listen, there's someone I need to…talk to…for one of my other cases," Astrid began.

Hiccup cocked an eyebrow at her. "How loosely are we defining 'talk to' in this conversation?"

"I've gotten intel from him before; he occasionally does need threatening, when he starts rambling or when the information I want turns out to be on one of his clients, but other than that he's pretty accommodating. Anyway, I'd like to introduce you to him."

Hiccup stared at her for a moment, as though searching for some ulterior motive. Then he shrugged. "Sure. Now?"

"I can call him _now_ , but the info is usually better if we arrange a meeting. He's not sneaky, though he's often…more willing to trust than is necessarily wise, and will preserve the secrecy of people who in retrospect should have been turned in right up front."

A smile touched his lips. "I think I already know _of_ him. Does he run a trading ship?"

"Uh-huh."

* * *

"My dear Lady Astrid, surely you are aware of my honor in regards to client confidentiality?"

"Mr. Johann, I _know_ he bought something very large from you." Astrid could feel a headache coming on. It had taken twenty minutes just to get this far.

"If you know, then why ask at all?"

If you delivered it for him, I need to know where; if he picked it up, we need a license number. Look, Savitch has been wanted for assault and armed robbery for the past four months! You're not dumb and you're not _that_ unobservant, so I'm amazed you even let him on your ship!"

Johann waved his hands in what he evidently thought was a calming manner. "Darling, I assure you, I've always been perfectly safe."

Hiccup had been a silent observer up until this point. Now he cleared his throat. "By any chance, did you pay for your 'perfect safety' with a heavy discount?"

Astrid shot Hiccup a warning look.

Johann faltered. "I don't…generally…discuss my business practices…"

"So you did." Hiccup leaned forward slightly, fixing Johann with a level stare. "So you're not getting paid the full amount for your goods, when this Savitch comes around. So, you're being cheated – but you're 'perfectly safe'."

Amazingly, Johann was getting twitchy under the eyes of this thin boy. "Well…erm…"

"I highly doubt you have any decent promise that he won't rob you anyway one of these days, taking back all of his money _and_ cleaning out the last of your goods. Do business with his kind, you always come out the worse in the end."

Astrid watched, fascinated; she hadn't known Hiccup could be that intimidating without so much as raising his voice or pulling his gun out. All he was doing was staring at Johann – and he also suddenly had more _presence_ in the room.

"On the other hand, you don't owe him anything. You tell us how to find Savitch, and we bring him in; then you really will be _perfectly safe_ , and you'll have all your goods to sell at full price. That's a much better deal, isn't it?"

Johann looked pleadingly at Astrid. "All right, all right…I did _not_ deliver this one, and his van had no plates, but he probably took it to the warehouse at the far north end of the harbor. I…overheard his discussion about it, on the phone. Now, if you would please take your scary little partner and go? I must lie down before my next appointment."

Astrid wanted to laugh at the declaration of "scary" – except that would have been rude, and Johann clearly believed it. "Thank you for your time, Mr. Johann."

Hiccup smiled as he stood up. "Pleasure doing business with you."

Johann shuddered.

Not a word passed between the partners until they were back in Hiccup's squad car. Then Astrid eyed Hiccup questioningly.

"Where did you learn your intimidation technique?"

Hiccup paused in the act of turning the key. "Dad."

Astrid snorted. "You're not big enough to pull off the chief's style. Certainly not well enough for anyone to call you _scary_."

Hiccup shrugged and cranked the key, making the engine roar to life – and smirked a bit. "Funny, that. I wasn't expecting it to work that well, _because_ of my lack of size. Actually, there is a part of Dad's technique I can do: focus. I was a…a fox, hunting a big rabbit. Predator giving prey every scrap of attention. Tell me _you_ wouldn't have been even a little bit nervous under that." He started out into the road.

At least he'd said _fox_ and not _wolf_ or _tiger_ ; Astrid would never have been able to take that seriously. She was already smirking just imagining Hiccup as a little brown fox. "What do you do, try to intimidate yourself in the mirror?"

The cruiser suddenly lurched off-course, nearly colliding with another car. The horn terrorized Astrid into silence for about two minutes as Hiccup wrestled back into the center of his lane and adjusted his speed.

"And you complain about _my_ driving!" Astrid finally got out.

Hiccup didn't apologize. Or defend. Or even respond. He kept his eyes fixed on the road and his hands wrapped around the wheel; his face was as pale as his tightly-clenched knuckles.

 _Scared yourself too, did you?_ Astrid left him alone for the rest of the drive, instead taking the radio and calling for backup to meet them at the warehouse.

The silence continued between them after they stopped in a side alley near the warehouse and Hiccup radioed in their position. Astrid drummed her nails on the dashboard, contemplating her next move with her partner. Something had gone very wrong, but she wasn't sure what would fix it.

"Anyway," she finally said, "Thanks for reasoning with Johann; and you did a good quick job of it."

Hiccup smiled slightly. Then he spoke to her for the first time in ten minutes. "Mirrors freak me out."

Of all the things Astrid had expected him to say, it wasn't that – although it sounded sincere in spite of being shocking. " _That_ was what…you…but what's wrong with mirrors?"

"Er, well, you know…I avoid looking in mirrors as much as possible because the guy staring back at me could never, ever grow up to equal my dad…and if I used a mirror, I'd have to acknowledge that that guy is me. Does that make sense?"

It did – sort of – but Astrid sensed it wasn't the whole explanation. Somehow, it just didn't seem adequate grounds for causing a near-accident. There wasn't time to press, though, because the rest of the force started radioing in that they were in position to take the warehouse.

 _Later. Maybe much later._

Astrid filed the mirror question away along with _why so intent on recruiting the Night Fury_ and _where did all those scars really come from,_ and got out of the car. It was showtime.

* * *

The police raid on the warehouse had gone without a hitch. They got Savitch and his crew, and an easy three truckloads of weapons. Yet, Astrid still felt like she'd missed something critical.

It must not be that case. It must be her partner. She felt like the reason for his weird behavior was right in front of her face, and she couldn't see it. Being so close to an answer and not being able to face it was maddening.

A lot of the senior officers held that sleeping on a problem like that sometimes worked; that the solution would come to them in a dream, and when they woke up everything made sense. Astrid would love to give that a try, except for one problem: her brain wouldn't shut up long enough to let her sleep. She'd been tossing and turning for the better part of an hour.

Finally giving up, Astrid got out of bed and fetched a notepad. She then proceeded to write down all the odd things about Hiccup that plagued her.

 _Wants to recruit Night Fury – was sure NF could be recruited before we ever contacted him!_

 _Not all of his scars can be accounted for by that Monstrous Nightmare attack three months ago: too many are new, not enough of them look like they were caused by MN weapons; bar fights?_

 _Strangely large capacity for intimidation on no practice;_

 _Hates mirrors; not because of comparing-self-to-chief – at least not just because of that; why else?_

Astrid considered her list for a moment – and suddenly remembered when they'd first given the twins that siren. Tomah had swung his hands to give both of them hearty slaps on the back, and while Astrid had taken the blow in good humor, Hiccup had shied away; Rowan had tried to grab both of them in a big hug, and he'd stepped back to let Astrid take all the love. Neither twin had looked surprised at Hiccup's behavior – for more than a few seconds, anyway – so it wasn't a "he was like that all the time we've known him" thing but it also wasn't a totally new thing. Three months, perhaps?

 _Dislikes hugs and back-slaps; MN related?_

Considering herself done – for now – she looked the list over again. Again, she felt like the answer was right in front of her…like everything on this list was connected together by one crucial detail…but she couldn't, for the life of her, think of what it could be.

"I'm missing something," she finally said aloud.

She hated that: being one fact short of a full case. While she was on the subject, she also hated the "can't see the forest for the trees" feeling. _What was she missing?_

Coffee was going to be something of a lifeline tomorrow.

* * *

 _ **Author's note:**_ _Cookies for everybody who can guess what "forest" Astrid's not seeing – or more to the point, why exactly she's not seeing it! ^_^_


	5. Chapter 5

Hiccup's "costume" as the Night Fury was very, very simple. No shirt, because it would hinder his wings; no foot coverings of any kind, because in flight his feet spread into near-wings themselves for stability and steering. He'd had gloves for a while, and then discarded them when he'd found that his dragon prints only bore _extremely_ _vague_ resemblance to his human prints; he gripped better without the gloves anyway.

All he had (besides the cowl) was a pair of close-cut dark pants with slits high on the outer edge of each thigh for a couple of stabilizing fins to spread through. In the last month he'd been adding pockets – figuring out how to put them in so that, even full, they wouldn't interfere with his flight line – so he could carry little…not-quite-legal crime-fighting devices that he made in his off-hours. Now, flying to the used-car lot, there were a few things in those pockets that weren't for him.

Astrid had her gun out when he glided into the used-car lot, but she wasn't aiming it: she was playing with it, hitting the cartridge release and then loading it up again. She looked skeptically at him as he touched down on the bumper of the nearest vehicle that wasn't hers.

"Somehow, I find it hard to believe your eyesight and hearing is _that_ good. That you would know if it was more than just me in a place with this many cabs."

Hiccup shrugged, his wings flicking to what he referred to as their active-rest position, and readied his Burn Voice. " **I have night vision, not X-ray vision, so I'll give you that one. But almost all you cops are too clumsy to move around silently in the confines of a cab, and you're not making enough noise with that gun to hide anyone else's movements.** " Mostly bluff: any car with a decently-padded interior would muffle things. But she didn't get to know that until he trusted that she would trust him.

Astrid made a noncommittal noise and slammed the cartridge chamber shut. "So. Your audio suggestion proved sound…" her eyebrow lifted at him, "…pun intended; any other ideas for me?"

" **Oh, I might have a few tricks up my nonexistent sleeve.** " Hiccup flicked at imaginary cuffs. Then he slowly pulled two items out of his back pockets: a carefully-wrapped package of the strange grass that had stoned him so completely when he'd crashed in it, and something like a texting version of a walkie-talkie. He tossed the package into her lap first. " **The first time I tried to fly –** _ **really**_ **fly – I crashed in a big field of that grass. It had the effect of some euphoria-inducing drug; that was the happiest I'd ever been in my entire life, and if I'd been attacked I probably wouldn't have been able to defend myself. Hours before I sobered up.** "

She opened the package and cautiously sniffed the grass. "So it's like catnip?"

" **At least on me.** "

That got an eyebrow cock. "We've already established that you don't experiment on your fellow weredragons."

" **We've also established that they're not my family. I actually would have no qualms at all about experimenting on them, except I don't have any place to stash them for experiments.** " Waving the gadget, he offered as explanation, " **I thought you might like an alternative to these nocturnal visits; this way you can text me if you think of questions later.** " Eyeing her carefully, he tossed it to her.

She caught it deftly one-handed – left-handedly, no less; Hiccup was impressed even as he acknowledged that she would never take her dominant hand off her gun in an uncertain situation. "Text? Not call?"

" **I'd rather not use this low burn more often than I need to.** " It wasn't until after he said it that he realized he might have betrayed himself.

Astrid scowled. "Wait…are you telling me you're disguising your voice?"

Hiccup thought about that for a second, trying to decide if admitting that he was would be a problem – but before he could make up his mind, Astrid went on as if the answer really had been yes.

"Odin's Breath, _why?_ "

For a long moment, Hiccup just stared at Astrid's incredulous face. Then he grinned – he couldn't help it – as it dawned on him that his secret was perfectly safe. Nobody would ever just guess that Hiccup Haddock the lab rat moonlighted as Night Fury, because of a hypothesis that was technically unproven but so commonly accepted as true that nobody ever questioned it; a hypothesis that was, in his case at least, false.

 _Weredragons didn't shapeshift._

At no point, in all of "Berk Watch vs. Helheim's Gate" history, did a weredragon suddenly morph into a human upon being killed; at no point did one ever turn human to plead for its life, and in fact they didn't show enough intelligent thought to consider that. Nobody on the force had ever even considered that there might be "sleeper" dragons among Berk's population, waiting for the full moon or whatever triggered a transformation in those mad-dog raiders – and if there was evidence of regular shape-shifting in the bodies they studied, they didn't know how to recognize it.

Hiccup managed not to laugh, but steam hissed out the corners of his mouth to betray his effort. " **If you ever figure that out, let me know and I might just** _ **give**_ **you a blood sample! As a reward!** " Still fighting laughter, he sprang into the sky and rolled a loop-the-loop before flying away.

* * *

He was still in high spirits when he went back to work; he didn't quite _ignore_ the briefing as Astrid played the – rather short – recorded conversation for Stoik, but he spent a lot of it staring at the wall and trying not to grin.

When the recording was over Stoik leaned heavily back in his chair. "This Night Fury reminds me of someone, but I can't think who," he admitted. Probably the big man didn't want to think _who_ , because then he would be acknowledging a weredragon as human.

"I was sorely tempted to shoot him when I realized he was laughing at me," Astrid sighed.

"I…don't think he was," Hiccup interjected, still smiling. "His attitude made _me_ think that he was laughing at some private joke."

Stoik glanced at Hiccup. "A joke on whom?"

Hiccup shrugged widely. "On us, until we get it, and then it'll be on him."

Astrid shut her eyes tight. "Hiccup, _please_ tell me you didn't grab a drink on your way to the office."

"What? No! Do I look drunk to you?"

"More like you've been eating this dragon nip. Speaking of which…" Astrid turned her attention back to the chief, "…request permission to make some new gas grenades."

"Permission denied." Stoik made some notes on a paper. "The siren was one thing; he told you it would work on other weredragons. But there's no evidence that this grass will have the same effect on all dragons that it had on him, and I won't waste resources on a gamble. First we're going to catch a weredragon or two and run some tests."

"Right, because that's not a waste of resources at all," Hiccup murmured, still smiling a bit.

"Did you say something, Officer?"

He spoke louder. "No, sir."

"Good." The chief waved them out the door.

"That went well," Astrid commented as they closed the door.

"I _do_ wish he'd been willing to make the gas," Hiccup sighed.

"Night Fury didn't know if this dragon nip would work on anything other than himself; research is fair. And we do have a few captured weredragons, remember."

Hiccup thought for a minute and remembered when they'd tested the first siren, two Deadly Nadders had been taken prisoner. "True."

Fisher caught up to them. "What's this I hear about the Night Fury disguising its voice?"

Hiccup nodded in greeting. "He called it a 'low burn.' I guess what he does is call up a little of that explosive fire and hold it in his mouth while he's talking."

"Makes his mouth glow," Astrid added.

"Huh. He wasn't doing that when he shouted at me before," Fisher mused.

Astrid looked at Fisher more carefully. "You're sure."

"I'd _definitely_ remember it if his mouth were glowing. I wonder why he felt the need to disguise his voice…"

"I asked. He didn't give a straight answer." Astrid scowled. "In fact, he didn't give _any_ answer – he basically told me to guess."

"A guess…" Fisher thought for a moment, his round face scrunched up. "When do you suppose his fire developed all the way?"

Astrid shrugged and pulled out the texting toy. "We could ask, I suppose. See if he's awake."

While she typed her question Hiccup thought about if the answer was worth the risk. He could see where Fisher was going, of course: maybe the firepower finished developing _after_ that first meeting three months ago, and now Night Fury couldn't speak English without actively restraining the fire. The answer, however, would blow that theory.

His version of the device thumped lightly against the base of his ribcage. He didn't have to pull it out to know what the text said, because he was reading over Astrid's shoulder: _When did your fire stop growing?_ If he was careful, he might even be able to reply without leaving his desk. It would take time, but as far as they knew the Night Fury was being roused from a morning nap.

Discreetly – he hoped – he slipped his hand between the buttons of his shirt and started typing blind. Fortunately the reply he had in mind was short; a longer one would require more planning, with the occasional both-hands-in-plain-sight.

Just about a minute later (long enough for Astrid to be seething impatiently, even though she _knew_ that Night Fury might be asleep) the visible device made a little electronic _ding_ , making Fisher jump.

Astrid pounced on it and looked at the screen as though it offered the key to enlightenment.

"Well?" Fisher asked shyly.

"It says, 'first week'," Astrid replied, studying the words over and over. "That's it."

"So…how far into that first week was his debut on the streets of Berk?"

Astrid's fingers flew over the keypad, asking how long he had been a weredragon when he first showed his face in public. Only after she punched Enter did she comment, "Our discussions about time have always been a little…vague."

Her typing that time was a little fast for Hiccup to be _sure_ what she said, but since he was sitting right here listening to the conversation he knew what the question was. He typed his answer and sent it – faster than before, because he hadn't removed his hand after the first message.

Astrid looked at the screen again. "'Nine days'."

"So that low-burn voice thing is something he's _trying_ to do," Fisher mused. "Why now? And why didn't he do it when he shouted at me?"

Hiccup withdrew his hand. "You said that everything was happening really fast…maybe he didn't think to disguise his voice then," he suggested. "Also, that wasn't an interrogation situation; the odds that anything would be recording in the area were pretty low. Talking to Astrid, he probably suspects that she's recording him and wants to make sure nobody will be able to place his voice."

"But _why_?" Astrid demanded again. "Who was he that he would want his human reputation protected?"

Hiccup took a deep breath. This was risky, big-time, but it was a contribution he could make to the Night Fury case. "There might be a way to find out."

Astrid looked at him expectantly.

"Let's assume all the hard facts he's given us are true. We know he's been a weredragon for about three months, and that he's less than twenty years old."

"But he must be _close_ to twenty," Fisher interjected. "I remember he looked…mature."

"And we know that he knows Fisher, at least well enough to identify him as an Ingerman. _That_ , all by itself, means he was a local at one point. So we check the Berk census records and find how many young men of the right or nearly-right build went missing three months ago."

Astrid frowned, thinking the suggestion over.

"That could work," Fisher agreed. "I can't think of anyone I know personally who went missing right around that time…"

Astrid flinched.

So did Hiccup. Reminding himself that Fisher might not be counting him among the "missing," since he was very obviously _here_ right now, didn't help much to ease the stab in his gut.

"But the records are a good place to start."

Astrid looked at Hiccup. "Wouldn't your dad see this as a deviation from the Night Fury case?"

Hiccup spread his hands. "Why would he? We're still investigating the Night Fury; we're just investigating who he was before he became a Night Fury. He obviously still thinks like a human, so if we find out what kind of a thinker he was while still a human we can figure out how to trap him."

Astrid paused. "You have a point. So do we ask permission now, or forgiveness later?"

"Um…" Hiccup thought about that. Last time they'd "deviated," they'd gone the forgiveness-later route because they wanted to save time and avoid the bureaucratic red tape; this time, he really didn't care how long it took to get those lists. "Let's get permission for this one. No point in getting another black mark on our names."

* * *

Besides the Nadders, there was also a slightly-overweight female Gronkle in custody; all three of them were extremely hostile and snappish when allowed to come off the tranquilizers, and the only way to give them the grass was in the form of small sacks thrown through the doors.

The results were incredible. The Gronkle had no sooner torn into the bag with her teeth when she started to relax; both Nadders were considerably happier after just a whiff of the grass, and were rolling around in ecstasy once they'd eaten it.

 _Then_ the chief authorized the production of dragon-nip gas grenades. He didn't give the job to Hiccup and Astrid, though, he put Fisher on it. As a kind of compensation, near as Hiccup could tell, he gave them that access to the missing-persons list.

"Might as well notify the poor devil's family, after all," he muttered into his beard as they were leaving.

Hiccup wondered as he ran the search just how many people had gone missing at the exact right time. Surely not many; Berk wasn't _that_ heavily-populated, and there weren't many raids that month.

As it turned out, counting himself, there were three. One turned out to be a surprise.

"Dagur? He went missing?" Hiccup stared at the screen, hardly believing it. "How did I not hear about this? He vanished _before_ I did!" Not much before, or he wouldn't have turned up on the specified search, but still before.

"Night Fury is _not_ Dagur," Astrid commented from her desk without looking up. "Not unless turning into a weredragon gave him a huge personality change in a positive direction."

Hiccup pretended to think about it. "Unlikely. If he's a weredragon, he's one of the mindless ones raiding us." There was no way a turning would make Dagur sane. Not when Hiccup had had to struggle to maintain his own mind, and still had doubts that he'd completely succeeded.

"Enjoying every minute, I bet." Astrid pushed back then, and looked over Hiccup's shoulder. "Who else is on the list?"

"Me – for the sake of completion – and somebody named Warren…how…how do you pronounce that?"

Astrid squinted at the surname, _Houghe_. "I think _hawg_ ," she drawled. And I think that's our guy, since you obviously don't have wings."

"How do you know?"

* * *

 _ **Author's note:**_ _I know this is a little short, but it's too perfect. Cliffie, muahahah!_


	6. Chapter 6

Astrid left the training grounds before Hiccup could put his shirt back on. She needed time to adjust to this strange new side of her partner. _When_ did he get that tattoo? _Where_ did he get it? More to the point, how did he survive getting one _that size?_

Most people who wanted wing tattoos just went for open wings on the shoulders or closed wings on the whole back; _Hiccup_ had bat wings wrapped around his entire ribcage like a vampire corset. And, as if that wasn't enough, they were completely colored in (iron gray with various shadings) – not a patch of normal flesh color anywhere within the boundaries of the tattoo.

He had to have been either blind drunk, or on some really powerful drug. Nothing else made sense: no way was his pain threshold _that_ high.

 _A drink sounds good at this point._ She went straight home to brood over a beer.

Interestingly enough, it probably explained why he'd been shying away from physical contact – hugs in particular. That much ink, heavily applied via needles over so much of his torso…it would be weird if he _wasn't_ really sore for weeks afterwards. Then it probably just got to be habit, dodging touch.

* * *

As she nursed her beer, shock receded and a memory surfaced: the stupid grin on Hiccup's face while she'd been gaping at his chest. He looked so outrageously pleased with her reaction, and almost – _almost_ – like he thought she was stupid.

 _No, not stupid; like he knew all the questions rolling around in my head, and considered the answers so obvious that it was funny I didn't already know them._

That didn't make her feel any less grouchy. She slammed the mostly-empty can down and pulled on her braid with both hands. "Arrogant smart-mouthed little…Hiccup and Night Fury are exactly the same!"

And she went completely still, eyes wide.

When the words first left her mouth, she was simply thinking of attitude. After she'd had a chance to hear them, however, pieces began flying into place. Both were attacked by dragons, the same length of time ago. They seemed to be the same age; she was less sure of the Night Fury's physique, since he preferred the security of shadow, but that also seemed to be close. And the only way Bad-Liar Hiccup could have told the Chief – so freaking _believably_ – that he'd been there for the interview was if he really had been there. _As the Night Fury?_

 _But weredragons can't shapeshift,_ Astrid wanted to object – except even as she thought that, she saw the problem with that "fact." Just because nobody had ever _seen_ a weredragon transform, didn't mean they couldn't. The Night Fury still had all his human intelligence so, assuming he could return to human form, he could pass undetected among human society.

Provided nobody discovered his wings.

Hiccup had very carefully _not_ invited Astrid to touch that so-called "tattoo," and she hadn't; what would she have felt if she had? Plain human skin…or delicate bones and leathery membranes?

 _Stupid: there isn't a tattoo parlor on Berk that does work that big._ Even if there was, it would be so freaking expensive (all that ink, and how many hours?) that Hiccup would never have been able to afford it. And even if he could, why the heck hadn't he showed it off? Scott and the twins would have been drooling over it; he'd have instantly been a lot more popular.

Wondering in silence was not Astrid's style: the minute she had a suspicion, she was back on her feet and rushing for the door. Hiccup lived in her apartment building – Scott used the "we're neighbors" line both to flirt with her and complain about his cousin – but she didn't know what floor, so she went straight to the reception desk and simply asked if he was in.

"Not yet" was the answer – and the very proper receptionist wouldn't just hand out Hiccup's room number, and the situation just didn't warrant waving her badge around. So Astrid settled down in the lobby and pulled out the Night Fury's text-toy.

 _You can shapeshift._

A long pause later the reply dialed in. _10 points for the smart detective._ She snorted; she could _hear_ Hiccup's snarky voice saying that. Her fingers flew as she composed her reply.

 _You're disguising your voice because I know you and would recognize it if you didn't._

Another pause, though a shorter one. _5 more points._

"Only five?" Astrid murmured. Ten points was obviously _completely_ correct; five points must be half-right. She thought for a moment and then typed some more.

 _And you know I'm recording you and don't want your real voice played back at the station._

This pause was even shorter. _20 points total, you've won a blood sample._

 _Do you WANT to be unmasked?_

Another long pause; this one was long enough that Astrid started to worry Hiccup was texting-and-driving, and had gotten in an accident. She let out a breath when the reply finally came.

 _I don't know. Why?_

Astrid considered for just an instant. _Because I think I know who you are. Hiccup Haddock, my partner._

There was no answer at first – and then Hiccup walked in the door, playing with his hat and looking antsy. The look in his eyes when he spotted her told her that she'd guessed exactly right.

"Can…if it's not completely presumptuous, you could come up to my apartment and we can discuss this…in private?"

Astrid nodded and stood. "Privacy is good. Incidentally, thanks for getting here before Scott; he'd probably have thought I was waiting for _him_."

Hiccup let out a slightly-strained laugh. "And misdirection rules the day: I said I wasn't up to do any bar-crawling, implied that you were making the rounds, and Scott's probably casing all the local joints hoping to spot you."

 _Guffaw_ was probably the only word for the sound that escaped Astrid, startling both of them.

"Wow, I…I thought you'd be offended. I mean, I implied you were bar-crawling…"

Astrid shrugged. "Ah, what's a little character assassination between partners?" she asked, a little surprised that she meant it. "And I _did_ have a drink earlier, so…that gives your 'misdirection' a taste of truth."

Hiccup smiled shyly and led her to his place. It was on the same floor as hers (the top one) and practically right next to the roof-bound stairs.

"Is this the part where you apologize for how messy it is?" Astrid teased.

Hiccup shrugged and unlocked the door. As he pushed it open he called, "Sharpshot? We have a special guest tonight, so you'd better not be planning an attack!"

There was no answer as they went in.

"Sharpshot?" Astrid echoed.

"My cat."

The place did smell like cat; not the _untended-litterbox_ reek or _toms-marking-territory_ stink, but a soft and musty _I-don't-regularly-vacuum-the-shed-fur_ smell. There were claw marks on most of the furniture (some of which were carefully stitched back together), the only cozy-chair _not_ clawed was covered in fine hairs, and there was dry cat food scattered near the kitchen door. All evidence of a cat left alone most of the day.

Other than that, it wasn't all that messy. Hiccup didn't leave things lying around, at least out in the receiving rooms; Astrid approved.

Hiccup waved randomly at the room. "So, um…if you don't mind cat hair on your clothes, you can take that chair. Or you can…find a reasonably intact spot on the sofa…or I can bring a chair from…"

Astrid sat in the furry chair – and was promptly swallowed by it. She tried to sit more authoritatively, found that she would have to stand up and try again, and decided it was too much work; opting for a more "I'm a lioness, disturb me at your peril" attitude, she settled back again and crossed her legs.

Hiccup watched her anxiously. "Really, if that doesn't work for you I can get a chair from the kitchen; they're all metal and plastic, he tends to ignore them…"

"This is fine." She might never leave this chair. "So…Night Fury."

Hiccup sighed and perched on the edge of the coffee table. "All right, you got me: the wings were real. _Are_ real. Sharpshot, manners."

Astrid blinked.

"He's, um, sniffing your boots. From under the chair."

"Is this how he usually greets guests?"

Hiccup shrugged. "Dunno; I don't usually have guests."

"He'll probably come out eventually. You said something about my winning a blood sample?"

That got a hollow laugh. "Right…stay there, I'll be right back."

"Forensics kit?"

"What? Oh right, you don't have yours with you…yeah, I'll get that too. I actually meant I can't…well, you'll see." Hiccup fled the room.

Astrid wondered what his problem was. And what definition he was using for "be right back."

* * *

It turned out to be maybe two or three minutes; Sharpshot had come out and was, near as Astrid could tell, trying to figure out how bootlaces worked when Hiccup walked back in.

"Sharpshot," he began.

"I have a cat of my own," Astrid told him – nearly losing her train of thought when she focused on him and saw that he'd abandoned his shirt. Had he changed his pants, too? She was reasonably sure he hadn't been wearing those earlier. "As long as this guy doesn't start clawing my feet, I don't care what he does down there."

Hiccup shrugged and put a box in her lap. "Do you…uh…want to watch?"

"The change?" Astrid glanced curiously at his wings. "I don't know. Is it gruesome?"

"I'm…not sure. It's hard to watch anything, let alone my reflection in a mirror, while I'm shifting. It _feels_ horrendous, though."

"Hmm. Tell you what, stay here and do it; if I can't handle it, I'll just look away." Even as she said those words, she resolved not to look away.

"Um." Hiccup shuffled self-consciously. Well, sure – he'd never morphed in front of an audience before. Then he closed his eyes and his body shivered, buckling to his knees.

Almost like a pair of curtains, two translucently thin pieces of skin slid back from over the wings – which drooped, shook, and lifted again to extend almost the length of the room. His chest looked shockingly white where the wings had been…and then black scales appeared, starting from within the tan marks and spreading out to hide the rest of his skin. His nails exaggerated themselves into claws; his ears got longer and more bat-like. His bare feet almost seemed to melt, spreading out into angled fans of skin and bone – like a goose's feet, only not quite.

It wasn't gruesome…it _was_ slightly unsettling, but horror movies used more disturbing sequences for their morphing werewolves. Heck, even some comedy films had uglier shape-shifts. The look on Hiccup's face – before the shift rendered it almost unrecognizable – wrenched Astrid's heart more than the transformation itself wrenched her gut. She released her breath in a nearly-silent sigh as she perceived that he was done.

Those large ears jerked in her direction, and Hiccup slowly raised his head. His mouth seemed wider and thinner-lipped, and his eyes were a bit bigger and a shocking, intense glow-in-the-dark green.

Suddenly Astrid had a fair notion how Hiccup had gotten answers out of Johann that day: he'd called on those predator eyes.

"Well, you're still here," he said dryly – and without using his burn-voice thing, so it still sounded just like Hiccup. He didn't make any of his usual sardonic facial expressions as he said it, though; maybe he couldn't. Maybe the scales drew his skin too tight for what a human would consider subtle.

"I've seen movies with scarier special effects," Astrid said lightly before getting serious. "The worst part was seeing how scared _you_ were and realizing you didn't like this alternate form at all."

Those eyes got even wider. "You, ah…noticed that, did you?"

"I'm a cop. I'm trained to see these things." Astrid struggled forward in the chair. "Let's get this blood sample, shall we?" She opened Hiccup's forensics kit and found to her relief that he kept it very well-organized.

"Right…let's get it over with." Hiccup shuffled closer, set his hand on the arm of the chair, and looked away. He held out his other hand to Sharpshot, who didn't run but seemed very disinclined to come closer.

"Standoffish much?" Astrid asked the cat.

"He went nuts the first time I shifted in the apartment. Wouldn't let me anywhere near him while I was a dragon, or for several hours after I turned back. This is pretty tame."

Finally Astrid found an empty syringe and readied it for use. She held it above Hiccup's wrist – and paused, not sure where to begin. The scales made an impenetrable barrier. "How…durable are these scales of yours?"

Hiccup looked briefly at the needle, and then examined his other arm. "There are a lot fewer scales on the inside of folding joints; try at the elbow. That's where they usually stick the needle at blood donation places anyway, isn't it?" He rotated his wrist so that the inside of his elbow was pointing up.

 _Fair enough_. Astrid took a firm hold of his wrist, found a vein (and he was right: the skin at that spot was just about as black, but unscaled), and pushed the needle through.

Hiccup flinched a bit. That was the extent of his reaction as she filled and withdrew the syringe. He started to pull away – and looked inquisitively at Astrid when she wouldn't let go.

"What _is_ your problem with being a dragon? I'd think it would be every little boy's dream to command a flying, fire-breathing beast – and little boys don't outgrow their dreams that quickly. You can actually _become_ that fire-breather…"

"And that's the problem." Hiccup stared at the floor. "If you had wings sewn onto your back, you wouldn't be able to control them even if their nerves were spliced into your spine: the human brain doesn't have the commands for that. The venom that turned me into this…it didn't just put wings on my back and a fire sac in my throat: it put the controls for those things in my brain. I still had to learn how to fly and spit fire, but I _could_ learn. I _could_ learn how to revert back to human form."

Astrid had never thought about what would have to be involved to be the Night Fury, but considering it now she could see how it might be a little disturbing. "Well, but…"

"And that's not even counting the animal instincts. You know what my first meal was, in that grove during my Lost Week? I was starving, I couldn't fly out yet, I was desperate – I managed to catch a trout, and swallowed it whole while it was _still alive_." Hiccup shuddered. "You don't want to _know_ what else I ate, when hunger pangs roused my dragon self; I avoided sleeping in dragon form when I could help it, which wasn't _very_ often because the nights were cold in there and I had to sleep on the embers in my fire pit."

"Hiccup…"

"I think I know why the weredragons don't act human: their minds probably broke down during the downloading process, between the survival instincts for their respective species and the controls for their fire sacs. There's so much dragon to them that there's no human left."

"Hiccup!" Astrid grabbed his ear and gave his head a shake by it. "Shut up, aim those big ears this way and pay attention!"

 _Now_ he was making a face: something between _gaping in astonishment_ and _grimacing in pain_. "Erm, Astrid…that hurts a little bit…" His other ear was trying to point at her, though.

She adjusted her grip slightly but didn't let go. "First of all, there are cultures where swallowing live fish is considered a beneficial health practice. The fact that _you_ did that, doesn't make you less human."

Hiccup's face twitched like he was thinking about a smirk. "I doubt they swallow trout."

Astrid twitched her wrist and bent his ear a little to silence him. "And so what if you ate garbage? In times of famine, people lower themselves to eat absolutely anything even remotely edible that might be nutritious; or to _do_ absolutely anything to procure 'real' food; or they die because being _civilized_ is more important than surviving. The will to live is strong in _all_ living things, including humans – what you ate when you had nothing else available _to_ eat doesn't make you less human, either."

"It's broader than that," Hiccup began. "It's what might have been stripped away…what else might have been put into…"

Astrid gave his head another shake. "Stop emoting and start thinking. You've been back in civilization for three months now, and weredragon raids aside there's been no famine. Have you ever gone hunting live game – or raiding trash cans – instead of going to a supermarket or restaurant and buying something?"

Hiccup blinked owlishly at her, slowly grasping that she now expected an answer. "N-no…"

"Have you ever had to _fight_ the _urge_ to hunt or forage? When you were really hungry, for example?"

"Um…" he flipped his hands in a helpless shrug. "Resist, yes…fight, no."

"How about simply walking into a store and eating raw product right off the shelves? I know you haven't done it – I'd have heard your dad shouting about it – but have you had to fight yourself not to?"

"Why would I want to do that?" He realized the answer – and the significance – almost before he finished the question, and his eyes widened. Astrid nodded approval.

"An animal wouldn't understand human barter systems; wouldn't even care. All it would see and smell, is a huge stockpile of food – and if it was even slightly hungry, it would just help itself." Astrid let go of Hiccup's ear and rubbed the back of his jaw. "If your _human_ moral compass is still intact after all this time with no signs of deteriorating, you have nothing to worry about. You're not going to snap."

Hiccup nearly sagged against her hand in relief.

Astrid's attention was attracted by an odd slapping sound, and she glanced at the floor. Hiccup was bouncing his leg, smacking his flat foot in a slow rhythm; the gesture reminded her a little of her cat's twitchy-tip tail. She let her fingers explore farther back and higher up, where scales gave way to auburn hair and the bare frills of his ear, and the rhythm got a little bit faster.

"I do not remember this from those two meetings."

"Hm? Oh, my hair? I have a cowl, but I only wear it for my night flights and evening meetings." There was something queer about his voice – not quite burn-voice, and not quite drunk, but…off. He seemed to be having a little trouble focusing his eyes, too.

Suddenly Astrid thought she knew what was going on. "Oh, you've got to be kidding me…" she grinned. If true, it was too hilarious. She _had_ to test this one right here and now.

Hiccup missed the subject change. "It's not that weird that I'd want to protect my head, is it?"

"Nope, not weird at all. Nobody gets to touch your mandible hinges." Astrid hooked her nails behind the spot in question, still grinning.

"What does that…? – _Oh!_ " Hiccup stiffened and gaped at Astrid as she started scratching. Then his eyes rolled as shock melted into ecstasy…and he essentially forgot he was supposed to be human. At least he was acting more like a big, lovable cat than a terrifying beast: his hands grappled at her arm, trying to keep her fingers on his chin, and he tried to roll into her lap.

"Hey, hey, hey – you're too big to do that!" Astrid laughed, quickly using her free hand to move the forensics kit off her lap and to the floor. Then she pushed at his chest, trying to establish some kind of boundary. "Come on, stay down…"

The Night Fury fell back – and pulled Astrid with him, enveloping both of them in his wings as he tumbled to the floor. Now holding her captive, he responded to her scratching by running his hands along the sides of her curves.

 _I should be strangling him…_ except she could hardly see _Hiccup_ in that happy dragon face. He was at least partially right about one thing: if there wasn't _actually_ a monster's mind lurking within his human consciousness waiting to ambush and consume him, there were certainly enough draconic stimulus-responses to send his brain into a low-energy state.

 _I shouldn't be encouraging this, anyway._ Astrid stopped scratching and pulled both hands down to pin them between their bodies.

The Night Fury stopped moving and prodded at her elbows, trying to make her hands come back. After a few seconds of _that's-not-working_ , he gave up and relaxed with a heavy, satisfied sigh – the kind of sound that made whoever happened to cause it feel exempt from a decade or two of Purgatory.

It also made Astrid feel kind of guilty. She was supposed to be _arresting_ the Night Fury, and now she felt like she would be betraying some soul-deep trust if she turned him in now.

* * *

A couple of minutes later the wings fell open and Hiccup ran his hands through his hair, fully in command of himself again. "I hate myself," he announced, matter-of-factly.

"Was that really so terrible?" Astrid teased.

"Well…" he drawled, clearly reluctant to say yes. "I suppose next you're going to say that there are pure-blooded human beings who derive catlike pleasure from an ear-scratching."

"I don't _know_ – but I'll bet you twenty bucks that there are." Astrid propped herself up and looked into his face. "You really need to understand just how wide and weird a term 'humanity' is."

That grin really was wide when he was Night Fury. "I could have told you _that_ , and cited the twins as proof."

Astrid laughed and stroked his face.

Hiccup shivered – and glared, hopefully in _mock_ -anger. "Oh no you don't: once was enough." He shut his eyes and called upon the transformation.

It was hard to tell where "Night Fury to Hiccup" began; by the time he was half-done it became clear to Astrid that it would _end_ where "Hiccup to Night Fury" had begun, and she got up so his wings could wrap around his chest properly. She chose to sit on the floor next to him, though, rather than stand.

"Are the wings always…where they are in the shift?"

Fully human again but still reclined, Hiccup opened his eyes. "Pretty much, yeah; them and the fire sacs – which, you can't actually see although I think some of the features that go _with_ the fire sacs can be spotted early if you look for them. Whatever part of my brain is in charge of the change…evidently is of the opinion that if I ever _have_ to be a dragon, what I'll need the very longest are the fight-or-flight options." Hiccup smirked at Astrid – an interesting contrast, since a moment ago he was showing off razor-sharp teeth in a much wider mouth. "So what is that, human or dragon?"

Astrid rested her hand on his chest. She could feel the finger bones of the wings, but faintly – the tightly-drawn sheet of skin blunted the edges.

"Human enough."


	7. Chapter 7

There was a surprise on the whiteboard, signed by Astrid, when Hiccup returned to the precinct.

 _PINNED BY A WEREDRAGON?_

 _OUT OF AMMO?_

 _(rough sketch of a dragon's jaw in profile, with an arrow pointing at the back of the lower mandible)_

 _SCRATCH HERE_

"Very funny," Hiccup muttered, studying the makeshift sign. Then he joined Astrid at his desk. "Did a little research last night, did you?"

Astrid made a perky, affirmative noise around her coffee. Then she favored him with a _very_ satisfied expression. "Here's a mouthful for you: _autonomous sensory meridian response_. Shorthanded as simply ASMR."

Hiccup thought for a moment, translating all the words. "Okaaayyy…"

She pointed at her computer. "It's described here as a 'distinct, pleasurable tingling sensation in the head, scalp, back, or peripheral regions of the body in response to visual, auditory, tactile, olfactory, or cognitive stimuli.' Not a lot of real scientific research has been done on it, because not everybody has this thing and there's no _one_ stimulus that triggers it in everybody; still, there are literally thousands of people subscribing to 'ASMRtists' who make videos with these triggers and post them online."

Hiccup looked at the screen. "Huh. So this is your proof that my reaction last night was a normal one?"

Astrid fluttered her fingers in his peripheral. "You owe me a twenty."

"Put it on my tab." He scrolled carefully through the article. "Interesting." After a minute he closed it down and settled in his chair. "What did my dad say when he saw your whiteboard art?"

"I was still reading that." Astrid seemed disinclined to reopen the article again, though. "Anyway, to the best of my knowledge he hasn't seen it yet."

"We, uh…" Hiccup dropped his voice. "We never did record anything last night. How are you going to explain…?"

"That's easy. I met the Night Fury while bar-crawling, we snuggled in a back room until I accidentally got him rolling in my lap, and I got a blood sample from him while he was still high on kitty-scratching."

Hiccup choked on a mouthful of coffee.

Astrid smirked at his reaction. "And I didn't call in with an arrest because by the time anyone got there, he'd have left. I wasn't armed in the bar, I was technically off-duty."

"Well," Hiccup gasped when he was able to breathe again, "What's a little character assassination between partners?"

"That was my line." Astrid swirled her coffee. "I'm actually hoping he doesn't ask, because that story kills _my_ character almost as much as it kills yours."

"Why would…oh. The snuggling part?" Hiccup wished they had snuggled. Besides the part where he was out of his mind and had her trapped in his wings. But Astrid had left not long after that, probably to spend the night researching "humanity" explanations for his behavior so she could win that twenty. "Well, I'm sure you can spin it so that it's all my fault."

"Oh, that was happening anyway."

"Of course it was." Hiccup wasn't even offended. It wouldn't be the first time he wound up…something of a scapegoat. And this heavily-modified tale would go over better than the truth, at least right now. "About the blood sample…"

Astrid cocked an eyebrow.

"Does it count as progress that the Chief needs to hear about… _before_ , or _after_ , we run tests on it?"

The other eyebrow lifted. "Do you ask permission to run tests every time someone drops something off at the lab?"

"Uh…no, actually. But this is the first case I've ever worked where he demanded regular updates."

Astrid rubbed his shoulder. "We've already been bending protocol to kingdom come on this one. Your dad and most of the force wants Night Fury _dead_ , and…" she trailed off with a pained expression, belatedly remembering that Hiccup _was_ Night Fury.

Hiccup shrugged and lowered his voice. "What he said to me in the briefing – before you came in – was that we had to 'bring him in or bring him down'. Either-or. If he can just be made to understand that the Night Fury has skills and information that would be valuable to have on his side, he can get everyone else to stand down."

Astrid favored Hiccup with a strange look.

"What?"

Her reply was so very, very soft that she was clearly counting on his still having dragon-hearing even in human form. Fortunately she wasn't _too_ quiet. "I thought you were going to say 'if we show him that the Night Fury is his son'."

Hiccup grimaced. "Yeah, I…really don't want to go there." He tugged on a desk drawer, frowning when it stuck. Carefully bracing himself against the desk and adjusting his leg so that a sudden give wouldn't make the drawer slam into his shins, he pulled harder.

"You don't seriously think your own father would pull out a gun and shoot you if…"

The drawer suddenly gave – and Hiccup nearly had a heart attack when a _bang_ sounded inside it. Greenish smoke poured out in his face, and he got a lot of it in his next startled gasp.

The smell was familiar. Like dragon nip, only way stronger…

" _Idiots_!" Astrid screeched before she started coughing.

Hiccup's last coherent thought – before he slid into a dark world somewhere on the far edges of consciousness – was _oh, crap._

* * *

Astrid was going to _kill_ the twins.

She wasn't a weredragon, but the gas made out of refined dragon nip was giving her a spectacular headache all on its own. All she could think was that she had to get Hiccup out of that office before he started rolling around in ecstasy.

Assuming he hadn't simply passed out. He wasn't assisting or resisting her efforts to move him; he wasn't moving at all. She was nearly carrying him like a sack of potatoes.

The gas was getting everywhere, making people cough and turn fans on to ward it away. It got loud enough that the Chief himself poked his head out of his private office, just in time to see Astrid stagger towards the door with her dead weight.

"What on earth…" he began.

" _Somebody_ …thought…it would be _funny_ …to hide one of those…new gas grenades…in Hiccup's desk," Astrid snarled between coughs. "He got a big lungful…getting him outside…for some fresh air."

Stoik growled. "At that concentration, it can't possibly be good for his health; call me if you think he needs a trip to the hospital."

Astrid nodded and stumbled the rest of the way out, flinching as he started roaring orders.

Unlike most buildings in Berk, the police department actually had a lawn of thick and even grass – which was good for Hiccup, because Astrid essentially just dropped him on his face. Settling next to him, she adjusted his position so that he was curled on his side; thus assured that he was breathing normally, she swept her hair back and took deep breaths of her own until her lungs felt clear.

"If there's anything left of the twins when the Chief's done, I'm killing them," she snarled.

Hiccup mumbled something about "vicious."

 _He's awake!_ Astrid pushed Hiccup onto his back and peered into his eyes. "Are you okay?"

Well, his pupils matched in size – but they were huge, making his eyes look more black than green. His eyelids weren't open all the way, either; he looked sleepy. "I, I…don't know…" His voice was clear, but slow. "I can't believe that bomb went and, and interrupted you, that was rude."

Rude? A gas grenade in his desk drawer was _rude_?

 _Dangerous_ was the word Astrid would have used: that gas was supposed to be at least partially diffused into the air before there was even a remote chance that a human could get a whiff, and Hiccup inhaled it nearly straight from the can. At that concentration, if his lungs were weaker it could have killed him. And…he was talking again.

"We were discussing…important stuff…and…secret stuff…did I ever…" and that grin was not reassuring, "Did I ever tell you, that…that I love you?"

Yep, Hiccup was definitely high; if he was supposed to have more of a resistance to dragon nip when in human form, evidently the refined version that was the gas cut right through it to reach the weredragon beyond. Calm and happy, and so relaxed that he'd rather lie on the grass than try to sit up.

One time Astrid had to interrogate somebody who had combined alcohol and drugs, with similar results to this; her usual techniques did not work and she didn't have time to wait for him to sober up, so she played along with his fantasy and got her answers that way. She resigned herself to the fact that _this_ conversation was going to be anything but perfectly logical, and adjusted her thinking accordingly.

"No, I don't think you've ever told me that," Astrid replied, deadpan. His arm was completely limp, except for a twitch in his fingers, when she lifted it to check his pulse. Which turned out to be normal for a sleeping person. "You claimed to hate yourself once; you'd just been enjoying yourself immensely, too." She pretended to consult her watch a moment longer, thinking, and then turned large "sad and anxious" eyes on his face. "You're not going to say that again about _this_ reaction, are you?"

"Well…" he eyed her face with an expression that was possibly supposed to be seductive, "…Not if you don't want me to…"

"I don't like it when people sit around whining about some personal feature they dislike. If you can't change it no matter how much you dislike it – or you don't dislike it _enough_ to try and change it – then just accept it. And I'm pretty sure this dragon-nip reaction of yours can't be changed."

Hiccup's face scrunched up like he was trying to focus; the resulting look was a bit pouty. "All right, all right…no moping, got it." His features relaxed again, and he squinted at her with another smile. "You should arrest your hair, it stole all the sunshine."

Astrid lifted her eyebrow sardonically. "I'll do that." She brushed her hand along the side of his face.

"So sparkly…" he shifted to nuzzle her hand, his eyes drifting closed. "…Your hand's warm. And so soft…how is your hand so soft when you hit people so much?"

"Maybe the fists I make protect the skin of my palms." Astrid felt rather proud of herself: she said that with all the solemnity of a formal recital, when inside she wanted to shake some sense back into him.

"Right, you usually _punch_ people. I knew that." His nose twitched slightly. "Sage…fish oil…beeswax?"

Astrid blinked, surprised. His sense of smell was that good? In _human_ form – so soon after having been saturated by refined dragon nip? "I make my own lotions most of the time. Fish oil and beeswax are both inexpensive, and sage is good for chapped skin."

Hiccup breathed deeply, drinking in her scent. "It smells good…"

Now that _had_ to be the dragon talking: no human that Astrid had ever encountered found anything made with fish oil to smell "good." Rowan liked those lotions, especially from back when Astrid was still working on the recipe, _because_ they reeked if they had too much fish oil.

"And you smell good; I've liked your smell ever since I had a strong enough nose to catch your smell…" he wavered, and his voice seemed to come from farther away. He was falling asleep. "…You smell like mag…magnificence…" and then he slid away entirely, before Astrid could decide if she was offended by his casual mention of something as personal as her _smell_.

 _And I can't even beat him up for this._ Hiccup's survival instinct was good enough that he would never have said any of that when sober. If he remembered this conversation later (and that wasn't a given), he would be terrified. Astrid made a mental note to reassure him if he did turn out to remember.

Strangely enough, she really didn't want to beat him up at all. In fact, she was wishing he could have said some of those things while he was sober…so that she would know if he meant it.

 _Will he ever say those three little words when he's_ not _high?_

 _Do I want him to?_

Astrid sat and thought quietly for a long time after that.


	8. Author's Note

Hey, everybody, just a little note from the author.

I was rereading this chapter the other day and came to the dissatisfying conclusion that Hiccup and Astrid's relationship was _rushed._ And that Astrid's connection to Night Fury was _forced_. I also seem to be in a bit of a corner - I don't know how to extend things from this point and have it be believable.

Therefore, I will be rewriting this fanfiction. I will be starting in a different place, answering the question I'm sure you all were asking: how exactly did Hiccup become Night Fury? Let's see how many of you had guesses, and let's see how many of you were right.

 _This_ fanfic will be staying up until I have caught the other one up to Astrid meeting Night Fury.

Cheers!

KillerGeishaYumi


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